You need to register your address. You can go to the immigration office to do it in person, or try online.
It is the rule called Section 38, the form is TM30 (NOTIFICATION FROM FOR HOUSE-MASTER, OWNER OR THE POSSESSOR OF THE RESIDENCE WHERE ALIEN HAS STAYED).
If your address is in Bangkok exactly (not that 'greater Bangkok'), you will go to the Chaengwattana Immigration office in case you want to register in person.
Website:
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Android app:
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(no IOS app)