Timeout server problem in Snapshot

I try to move one of sites within multisite to main site.
When restoring I'm getting info

Your web server timeout is set very low, 900 seconds. Also, it appears this timeout cannot be adjusted via the Snapshot backup process. Attempting a snapshot backup could result in a partial backup of your tables.

(it was initially 300 seconds but I asked my hosting provide to make it higher).
What setting would be ok?

Best regards,
Paulina