That sounds like you want to match any character, if that is the case you won’t need a regular expression.
Are there any characters you don’t want to match?
Hey Madhura Lendhe, there are a few ways of implementing this, as Robert mentions you might have other solutions besides a regular expression. However if you want to use a regex you can use the function isMatch.
You can implement this in your microflow and check in a decision split if the entered value is correct. You would write it like:
isMatch($entity/Name , '^[a-zA-Z]*$’)
This would check if the name only contain a-z and A-Z.
You can also add it in the text field itself, choose under validation>custom and then enter your regex with the isMatch function.
P.s. if you need a specific regular expression I would recommend to use a regular expression test tool found online to test your expression, a small mistake in the regex would cause it not to work correctly.