Adding characters in the word file

[Snoopy]

Take a look at rules

https://hashcat.net/wiki/doku.php?id=rule_based_attack

I know rule attack. But I need something to be able to change the letters to lowercase, for example, and a special character before them, and at the same time add randomly selected numbers

you can "stack or combine rules"

rulefile:
l ^! $1

pass:
MyPasswort

output:
!mypassword1