Tab: Marketing > Website (the Business: Website tab). Two text settings (global only), each taking a full URL or a site path:

• After Register redirect to – where a newly registered customer is sent (Sprwt appends `?newUser=1`, which is what triggers the welcome popup).
• After Login redirect to – where a customer lands after a normal login, after validating their email, or after completing two-factor verification.

Leave them empty to use the default landing pages. If a visitor was redirected to login from a protected page, that original page still takes priority over this setting.