First use was difficult, a moz code msg & add-on Read Aloud error msgs. Here's the soup I swam thru & it is working for me in FF 62.0.1. (1) This occurred likely from me not having understood the add-on doesn't have 2 EQUAL entry points for messing w it, so note ur entry point if checking out RA. For ex., with only my FF Home Page open (Top Sites, BMs, History), when I tapped the right upperhand 3 vertical dots on my homepage & selected Read Aloud as a direct access point from the drop-down, RA opened to its what sb Options page but was browned out & gave an error msg instead, BUT THIS WAS BC I opened the add-on from its direct access title (I'd thot at 1st on seeing a code error that I'd caused the error msg bc I didnt have open a webpage intended for reading, only my homepage--later I learned it reads many types of content); and so when I instead FIRST selected the (folder type) heading of my installed FF "Add-ons" & THEN proceeded to the Add-ons list & from there selected Read Aloud, I didnt get the error msg "Missing host permission for the tab", I saw the operational Options page, no error msg. Yes!, but it still wouldnt read aloud bc it couldnt, bc I had yet to tell it the language I wanted to hear. (2) IT WORKS, FINALLY, bc if the msg is, "Please sign in to use the Premium Voices", go back to the FF Add-ons list, & select Read Aloud; the Options page that opens will show (probably) the "Voice" selection as "DEFAULT". NOT GOOD. Get rid of the empty "Default" by selecting the voice; a drop-out of language choices is behind the placeholder "Default"--there is no voice that the add-on has defaulted to; RA is awaiting ur selection b4 it will read; & aft you pick a language, "Voice" selection will show "Auto select" not "Default" on RA's Options page. I selected Brit English & Read Aloud read a webpage, yes! I didn't try selecting other voices to see if all are active vs if selections are restricted based on my phone's location/country. I dont know that info, I only know that YOU MUST pick a language for RA's voice reader. Before I knew this simple step I read another reviewer asking the Dev sevl mos back about my same error msg, about prem voices, & I nearly uninstalled RA bc Dev answered with an apology that no purchase was avl yet thru FF, bc the Dev hadn't heard that the reviewer wasnt asking to buy Prem voices, only wanted the add-on to work 'out of the box' & wanted to know what more is required, what do we not know or haven't understood or havent been told? I ?'d if the error was bc RA thot I wasnt signed into my Add-ons or FF browser accounts, but I verified that I was & besides, I'd never known FF Add-ons to care if users had an acct. Then another reviewer from yesterday's date said a moz code msg appeared (Options page), that RA wasnt working, v FF 66.0.1. I'd gotten a moz code error msg too, sevl times, until it stopped & started giving the premium languages error msg. I dont know why it switched from moz code to premium lang as the error, but aft going back & forth opening FF tabs, clicking Read Aloud to hear IF it would read eventually, the Options page began showing prem lang access error msg not the dead-end of the moz code error & with that error msg the Options were avl, & tried self-selecting a language, thinking maybe Default is 0, & the app could work now, it read a webpage. Such a simple step. And now I wonder if going via direct access to open Read Aloud while the Voice was not selected, when it was showing "Default, if this combo is why I got the moz code msg, & I wonder had I not gone to RA via direct access, if I'd gone to Add-ons to access RA, if I might have only had 1 error msg to deal with & not the moz code error prior to it that delayed my getting to the important SIMPLE need to Voice select? (3) It was confusing to me that the add-on could read its "Test" biographical text every time I hit Test from the Options page yet I couldnt finagle it to read a webpage. Maybe an update to FF (mine is v66.0.1) caused the "Default" option of Voice to to zero out. Has anyone bought Prem languages bc of the error msg, e.g., bc RA wouldnt read more than its Test? I can see ppl uninstalling it thinking it doesnt work, but with many great 5+ reviews, it obviously has easily worked out of the box for many. (4) Oh, btw, when u look at languages, go to the very very bottom to see the choice of "Custom Voices"; this opens to 2 selections each requiring credentials entry for the AMZ Polly voices or API ID entry for the Google Wavenet voices (#new2me). This customization when looked at but not selected seemed to hang up bc aft backing out of it, back at the Options page, "Enable custom language" showed as the Voice selection for a short bit, but maybe the lag time is to serve as a temporary reminder of entry of info being needed still if choosing custom voices. No worry, it eventually phased out & "Auto select" appeared beside Voice selection. (5) For me it was a jagged learning process b4 finding the simplicity of making it start, & not a hard path, but a time-consuming one. I don't know, it makes sense to have to enter the language, but Default didn't ring bells for me, it looked already selected as if it was okay 'as is'. Best wishes to Dev & other users. Dev, I'll donate if it works to read books I have open. I need audio of books, I don't have a phone screen reader so this add-on might be an important help.