Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 8192 bytes) in D:\php\OOP\fpdf183\fpdf.php on line 1444 code example

Example 1: Allowed memory size of 1610612736 bytes exhausted

export COMPOSER_MEMORY_LIMIT=-1

Example 2: PHP Fatal error: Allowed memory size of 134217728 bytes exhausted

memory_limit = 64M;