Hello,
Please choose forum or mails, and do not mix them.
1/ Try to add the code in this area – https://prnt.sc/DRomNf6GaBHN
2/ Provide URL and temporary wp-admin access, do this via the form here in the Private Content area, we will check your settings and help.
3/ Let us know if any further assistance will be needed. Also, you can find videos about menus here – https://www.youtube.com/c/8theme/videos
4/ et-mailchimp dark classic-button
– here are classes, you can use them together or separately as in our examples
Regards