Replacement battery of my iPhone 12 draining quickly

Who replaced the battery? If it was Apple or an authorized service center, take it back and get it checked out.

If it was a third party repair shop, they didn't use a genuine Apple battery and there is no telling the quality of the battery they used. Apple doesn't sell parts to non Apple repair shops.

What is the current setting for Maximum Capacity on the battery?

Settings > Battery > Battery Health & Charging

If Maximum Capacity is not displayed, the shop installed the wrong battery

What are the apps that are using the most power?

Settings > Battery

Scroll down to see Battery Usage by App

Could you please answer the other questions that we asked regarding the apps that are using the most power?

Overall, how is the cellular signal strength received by your iPhone? How many "bars" do you see on average? A weak or fair cellular signal can requires up to as much as 10 times more battery power, as the phone is constantly searching for a better signal.

See

Test your iPhone battery for self-discharge

Check your iPhone battery for Self-Discha… - Apple Community

and

The last update killed my battery

The last update killed my battery! - Apple Community

I have like 3 bars mostly as I’m at home mostly I’m working from home.

Your battery will not work nearly as hard using a Wi-Fi signal compared to a cellular signal. If you are home most of the time, it would make sense to use Wi-Fi all the time......assuming you have a Wi-Fi router.

Do the first one tonight, exactly as described.