Usually, multi-languages applications struggle to give the linguists the context of each label.

Using string interpolation would allow you to type an expression that will be interpreted and concatenated according to variables.

Eg.

Hi dear {UserName}, this is a message to show you how string interpolation would be helpful for your project {ProjectName}.

To replace {UserName} and {ProjectName} for your value you will need to create a structure with these two properties and just assign it before sending it to the extension to be interpretated.