We have new setting "Allow PHP Execution" (in Security settings) that is disabled by default. That means eval() function is disabled. Of course you can enable this setting but for security reasons I don't recommend to do it. This old thing from v7 is sooo bad idea..
You can generate panel and put your php code to file https://www.php-fusion.co.uk/addon_ge...generator/ (the generator is for v9, but panels are the same for all versions). This method is much better and safer.