Thanks for RK’s kind and professional help. the issue was gone.
Final solution for this issue, For those experiencing the same problem
1) , add test.php(serch it in page)file to ftp(wp-config.php folder). right way to to open test. php. like?https://abc.com/test.php
2) ,add?IP + domain www.domain?into the?/etc/hosts?file
Check cmd: ~# tail -n 1 /etc/hosts
result: 1.2.3.4 abc.com wwwabc.com
