support of webforms .aspx pages in core

Question

1. I have a website using webforms, need to migrate to asp.net core 5, how it can be done. we are using webforms.aspx with JavaScript which calls our BL then BAL calls DAL .DAL is in entityfromwork 5.

1. how long support of webforms will be there? Do we have to change from scratch?

yours sincerley