As mentioned, TM30 form (notification of foreigners staying the facility) should have submitted by your landlord/hotel/condominium manager and you should have received the receipt.
In case you are asked for a TM30 receipt at the immigration office, you need to show that TM30 receipt. Just a lease contract is not a TM30 alternative. You may need to file TM30 by yourself if you don't have.
In Bangkok, they don't ask you to show TM30 receipt for 30days tourism extension usually, but not 100%. So check your landlord for the receipt first. If they wouldn't, be prepared for self-file.
For self-file in Bangkok.
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