How to get variable value from a file

Brennan

HI All

This is my first time posting question here. Hope I post in the correct forum.

I have a question about variable.

I have a file (test.txt) with content like:

my  name is $name

Here is my BASH script

name=Brennan

filecontent=$(cat test.txt)

echo $filecontent

I would like to display my result as  my name is Brennan. However, my script returns my name is $name

Could you please guide how could I get the expected result?