How to prevent Firefox on an https site from loading http content?

Question

Mozilla Firefox

I recently asked a similar question on Chrome ( https://toster.ru/q/152923 ), but now I switched to Lisa and ran into the same problem here. It is necessary to prohibit uploading images via http on https pages, all other content is blocked, and images are loaded ...
In chrome, this was solved by the --enable-strict-mixed-content-checking parameter, is there something similar in firelis?

Test site https://www.ssllabs.com/ssltest/viewMyClient.html shows that of "Mixed content" only "Images" are allowed.

Answer 1

Toggle Mixed Content in Firefox
Enter about:config in the address bar.
Find security.mixed_content.block_display_content , press the right key and select Toggle if the parameter is set to false .

Answer 2

Via addon:
https://www.eff.org/https-everywhere
https://addons.mozilla.org/en-US/firefox/addon/for...