Php7.3 error undefined function simplexml_ load_ string()

Generally, this is because php The expansion module is not installed simplexml As a result of , What I use here is php The version is 7.3.24, The installation method is

yum install php73-php-simplexml // install simplexml
systemctl restart php73-php-fpm  // restart php

If it is another version, it can be replaced correspondingly 73
And then print phpinfo() See the following module , Then the problem has been solved