<?php

$mixCheckResult = 'Update can not be applied';

if (!(PHP_VERSION_ID >= 70400)) {
    $mixCheckResult = 'This update requires a PHP version ">= 7.4.0". You are running ' . PHP_VERSION;
}
else {
    $sVer = $this->oDb->getOne("SELECT `version` FROM `sys_modules` WHERE `name` = 'system'");
    if ('13.0.0.B1' == $sVer || '13.0.0-B1' == $sVer)
        $mixCheckResult = true;
}

return $mixCheckResult;

<?php

$mixCheckResult = 'Update can not be applied';

$sVer = $this->oDb->getOne("SELECT `version` FROM `sys_modules` WHERE `name` = 'system'");
if ('13.0.0.B1' == $sVer || '13.0.0-B1' == $sVer)
    $mixCheckResult = true;

return $mixCheckResult;

--- 
+++ 
@@ -2,8 +2,13 @@
 
 $mixCheckResult = 'Update can not be applied';
 
-$sVer = $this->oDb->getOne("SELECT `version` FROM `sys_modules` WHERE `name` = 'system'");
-if ('13.0.0.B1' == $sVer || '13.0.0-B1' == $sVer)
-    $mixCheckResult = true;
+if (!(PHP_VERSION_ID >= 70400)) {
+    $mixCheckResult = 'This update requires a PHP version ">= 7.4.0". You are running ' . PHP_VERSION;
+}
+else {
+    $sVer = $this->oDb->getOne("SELECT `version` FROM `sys_modules` WHERE `name` = 'system'");
+    if ('13.0.0.B1' == $sVer || '13.0.0-B1' == $sVer)
+        $mixCheckResult = true;
+}
 
 return $mixCheckResult;
Upgrade script from 13.0.0-B1 to 13.0.0-B2
