How to enable java on mozilla?

HI, I would like to know how to enable any plug ins or extensions on new mozilla firefox, to get “art applets” to work on ark-making sites?java support is deader than a doornail, altho “oekaki” scribble art sites need it to “run art applets to draw and paint.” like Shi-Painter Pro,and Shi-painter programs?" NOTHING ON THOSE SITES WORKS ANY MORE!!NO JAVA!!AND internet explorer is crap full of bugs,no one can use it!!!how do i gety my firefox to make art applets run?please be exaCT,I’M A SENIOR,AND THIS IS EXHAUSTING ME!!THANK YOU!!

Take a look at https://support.mozilla.org/en-US/kb/npapi-plugins. The only way to use Java with Firefox is to download and install Firefox 52 (32-bit edition ONLY for Windows). After early 2018, there won’t be any supported way to use Java with Firefox. Ever again. Never.

In case you’re not yet ready for this transition to happen, the ESR (Extended Support Release) of Firefox 52 will continue to support these plugins until early 2018. Click here to download Firefox ESR.

Important: The Windows 64-bit version of Firefox 52 ESR only supports the Adobe Flash and Microsoft Silverlight plugins. If you also need support for Java or other plugins, choose the Windows (32-bit) download.