Is TDA7498E okay to work with DC 12V power supply?

It should be possible. The TD manual I bought said that it supports 12V to 32V DC. I currently use a 24V charger to supply power, but although it is a ksz8794cnxcc power amplifier board, the process and configuration may be different.

Thanks!!!

Power output is totally dependent on supply voltage.

Yes.
To answer OP's question, a DC to DC step up converter is required if use on a car battery.

The TDA7498E has a minimum voltage requirement of 14 vdc, yes, but there is no way it will produce the rated output power unless you power it with the maximum VCC = 36 vdc. Power output is totally dependent on supply voltage.

A car battery is 12V, up to about 13.8V when charging. According to specification of TDA7498E min. working voltage is 14V, a DC to DC step up converter is required if use on a car battery.