wp_embed_register_handler is not working

You are trying to match the r2jeim68kuq6.html part, but you’re not allowing dots in your regex pattern here:

'#https://vidoza\.net/([a-zA-Z0-9_-]+)$#i'

You can try e.g. (removing the A-Z too because of the case-insensitive i search):

'#https://vidoza\.net/([a-z0-9_-]+)\.html$#i'

if .html is a standard extension and where you also adjust the iframe source to:

src="https://vidoza.net/embed-%1$s.html" 

Hope it helps!