Get the tags in text format

Hello,
I am trying to grab just the tags used in a post. I tried searching but the keyword ‘tag’ actually pulls out other tags, instead of the function that can grab the tags of a post.

I am trying to do something like this:

<?php $posttags = get_tags(); ?>

When I use the_tags(), it prints out the data but I want to store just the tags in a variable like:

<?php $tags = “tag1,tag2”; ?>

Thanks in advance for your help.