Gmail may ask for verification to add a forwarding address or edit filters

Filters: creating a new filter, editing an existing filter, or importing filters. 

Forwarding: Adding a new forwarding address from the Forwarding and POP/IMAP settings. 

IMAP access: Enabling the IMAP access status from the settings. (Workspace admins control whether this setting is visible to end users or not) 

https://www.theverge.com/2023/8/23/23843682/gmail-verification-forwarding-address-edit-filters-protection