Regular expression for file access add-on in Flow

[User_home]

Nextcloud version (eg, 29.0.5): 26.0.13
Operating system and version (eg, Ubuntu 24.04): Debian 12
Apache or nginx version (eg, Apache 2.4.25): Apache
PHP version (eg, 8.3): 7.3

The issue you are facing:

What a correct set for regular expressions to use on flow app for file access control?

For example to block files like file.3dmbak i try to use ^.*.3dmbak$

It work on regex101, but flow return: "The given regular expression is invalid "

Kind regards.

[tflidd]

From the example shown when you create a rule, you just need:

/^.*.3dmbak$/i

and then if I try to rename a file to whatever.3dmbak, it does not work.