The da14585 serial port cannot output when the sending character is 0x00

Hello

I want to know how the da14585 chip serial port makes the character or string sent to be 0x00. The problem now is that when the string contains 0x00, all the characters after 0x00 cannot be output in serial, which is equivalent to that 0x00 is a character ending character. How to avoid the situation that it cannot output 0x00?

谢谢你！