I don’t see cellular button in my Apple Watch app

Please explain where you are looking and expecting to see a cellular button in your watch, because this is not something I expect during the pairing and setup process. See Set up your Apple Watch - Apple Support and use it as a reference so we all see the same script when you post back.

Please check you have had your network setup the cellular service to the watch, it needs to be configured as a second device on your iPhone calling plan so it shares the same phone number. Also please check exactly which version of Apple Watch you are using. Only Series 3 and Series 4 have standalone cellular versions, distinguished by a red dot or a red ring on the Digital Crown. If the watch doesn’t have red on the crown it doesn’t have standalone cellular.