As the title explains, how do I make a buyable ending and music easter egg and add it to my map?  Also, along with these two questions, I have a few others:

With the music easter egg, am I allowed to have custom music?
Is it more of a hassle to have custom music?
Also, with the buyable ending am I allowed to customize the text?

If someone could answer any or all of these questions that would be great, as a buyable ending, and music EE are just about the last things I want to add to my map. Thanks!

I use the search function on both UGX and zombiemodding but I only find posts containing those words, rather than tutorials on them. I somehow found a tutorial for a buyable ending on zombiemodding, which didn't work for me.

Edit: Funny thing. I tried searching for "How to make buyable ending" (Can't include a because it's too short) and this post was at the top XD

I looked up both "How to make a buyable ending" and "How to make a music Easter Egg" on Ugx with everything in general help set as the parameters. Not only that but I also looked on google. Still nothing. I looked on youtube, found a zombi3 kllr tutorial on a buyable ending, followed it perfectly, and got a bad syntax error. So for the buyable ending I found a tutorial that didn't work, and for a music EE I couldn't find anything. Should I just give up and release my map since these are such tiny details?  ???

Although I couldn't find a working tutorial for a buyable ending / music easter egg I still would like to thank you guys. Maybe next map will be luckier