My IPhone 11 Pro Max stays at 100% battery most of the day before completely draining

Is this the original battery or have you ever had it replaced. If so, by whom?

What is your battery health? Go to Settings>Battery>Battery Health>Maximum Capacity. If it's less than 80%, you need a new battery.

iPhone Battery Replacement - Apple Support

I got it replaced by a group of professionals in a store where they like do repairs, sell electronics, etc. Because of this I can’t see my battery health so I don’t know what it is.

The shop was not authorized to handle Apple repairs or service and as such, they installed the wrong battery in your phone.

Apple will refuse to even look at your phone now because of tampering by unauthorized persons.....which you call "professionals"......so your only recourse would be to take the phone back to the "professionals" at the shop that handled the "service" for you to see if they can help.

Also unfortunately, your phone now will have zero trade in value if you want to buy a new phone from Apple using one of their promotions.

If you had the battery replaced by someone other than Apple or an Authorized Apple Service Provider, that's correct, you won't be able to see Battery Health.

How long ago did you get it replaced? It sounds as if these "professionals" might not have done the replacement properly. If it was recent and they offer any kind of warranty on their work, take it back and have them fix it. If not, you can check with Apple to see if they will replace the battery. Since someone unqualified was messing about in the phone, they may not be willing to, though.