Firstly, it's about scheduling and prioritising. If anything comes up that might be a blocker, or has been blocking you, or will in the future, you mention that

Firstly, it's about scheduling and prioritising. If anything comes up that might be a blocker, or has been blocking you, or will in the future, you mention that as it relates to scheduling, and go solve the block whenever you want. There is zero expectation for you to wait for standup to raise any issue.