Hello, please ask a question. log error report, how to add export? Here is the error log. Is there any documentation about this?

All information about RouterOS is to be found here:
https://help.mikrotik.com/docs/
http://wiki.mikrotik.com/wiki/Main_Page
and of course this forum (use the search facility)

dstnat: in:pppoe_DX out:(unknown 0), proto TCP (SYN), 117.161.75.117:56018->106.42.162.62:22, len 60
This is the error code

You may want to start here
viewtopic.php?p=908118

dstnat: in:pppoe_DX out:(unknown 0), proto TCP (SYN), 117.161.75.117:56018->106.42.162.62:22, len 60
This is the error code

It is not an error code. It is a log message from a firewall NAT rule. It can be logged for success or failure, depends on what the rule says and what your intentions are.

Crystal ball must be on sale where OP lives