SimpleFill is an Extension App in the Brave browser that I use numerous times daily for filling in my email address, when I log into my email accounts and filling out Forms.
Instead of having to type the all the information in, I just paste it in with a couple of clicks with the mouse button.
A couple of days ago when I went to log into an account I brought up the SimpleFill and there was no longer any of my data available to paste in. :-(
It appears that the SimpleFill extension now wants me upgrade and pay for using it.
I was not impressed that it removed all the Form info information that I had entered into the Extension.
I could not find any info on the SimpleFill description page, that said anything about it now was a pay for Extension.
This issue with SimpleFill occured on 2 of my notebook computers. One runs Mint Linux, the other runs MXLinux.
So I ditched the SimpleFill extension and found another called Lightning Autofill.
At least it tells you that with the free version you are able to use it for 10 entries per day, which will probably be ok, for me.
Oh, that's sad that they did that. It's good that you found an alternative. Note that password managers like Bitwarden, which I use, will fill in forms, too. You can even use it only for that if you prefer.