How to use Safe Redirect Manager?

Hi,
I have a problem with this Safe Redirect Manager, which is already added in our site admin. I am just a beginner with this and need help.

I have an old page URL
https://www.kokkola.fi/tankar_2/yhteydet/fi_FI/ms_jenny_1/

and it should be redirect to this address
https://www.visitkokkola.fi/majakkasaari-tankar/

What should I write in textbox “Redirect from”? The whole old URL or just a part of it? If I check Enable regex, what happens?
And the other text box “Redirect to” goes this new URL, right? And the whole URL with https?

Thanks in advance.

Juha