We have an Integration that uses OAuth 2.0. The user always has to re-authenticate the connection every 7 days. Is there a way to extend it? We can edit the Refresh Token Validity but not the Maximum Time for Token Rotation. Not even sure which one relates to the user re-authenticate. It seems to be the second one.

That 7-day re-auth cycle is a classic NetSuite OAuth 2.0 gotcha with the Authorization Code Grant, cos it's the "Maximum Time for Token Rotation" (168 hours) capping refresh token lifetime, forcing full re-auth beyond that. You can't edit it directly (fixed), but bump Refresh Token Validity to 720 hours (30 days) for longer auto-refreshes before hitting the wall. For truly hands-off, switch to Client Credentials (M2M) Grant: enable it, upload a 2-year cert, and skip user auth entirely.

We've already set the Refresh Token Validity to 720 hours, but NS is still forcing the re-auth every 7 days. Am I missing something?

go for M2M.