Select the range using Smart Formulas, go to Actions, click on the "Selected Range" button, and wait for the process to finish.
Reasons to Refresh Smart Formulas:
Errors: You can fix some errors by refreshing formulas.
Re-generate: You can get a new result if you're not satisfied with the current one; it's very helpful for IMAGINE_X and SAY_X formulas.
Update Results: You can get the latest information if a formula using the Knowledge Base or Web information.
It's important to keep in mind that updating multiple formulas simultaneously can result in a longer waiting time.