Firefox, top menu Tools > Browser Tools > Web Dev Tools console opens > click on the right side on the smartphone icons,
you got this: (you can close the console, don't need any more as the "phone" version will stay)
click on the + sub-menu opens click on any > upload
Scroll down to click on your "face" at the very bottom to go to your "home" to check your picture
I never ever downloaded any facebouc, instagragram, whatsoever social sh.t on my phone, all via my browser on my pc
you got this: (you can close the console, don't need any more as the "phone" version will stay)
click on the + sub-menu opens click on any > upload
Scroll down to click on your "face" at the very bottom to go to your "home" to check your picture
I never ever downloaded any facebouc, instagragram, whatsoever social sh.t on my phone, all via my browser on my pc

Patrice