Y. SEO Premium how redirect a folder with an without slash?

You should check their knowledge base articles, and if you can;t find the solution then contact them directly through their website. There is only community support here.

barnez is absolutelycorrect. If you’re having issues with the Yoast SEO Premium, you can get premium support. We have a form at – https://kb.yoast.com/article/160-support .

Just click the Contact link in the right corner. ??

Found a solution:

The redirect (entered under the SEO > Redirects > Redirects tab) works for URLs with and without a trailing slash at the end.

(That was not the case with the redirections plugin, you had to create 2 redirects)

I’m glad to hear you got this solved, autoschieber!

~ Kim ~
Support at Yoast