Yes. Top right, on every page, tap-to-call on mobile. For call-first businesses it's the single highest-value pixel real estate on the site: visitors ready to act shouldn't have to hunt for the way to act.
Make it a real link (tel:) so phones dial it in one tap, and pair it with the hours if answering is time-limited. A number that rings into voicemail at 2pm erodes more trust than no number.
If you track marketing seriously, a call-tracking number can live here. Modern trackers handle number-swapping without wrecking your local-listing consistency, as long as your Google Business Profile keeps your real primary number.