Please help

I have searched everywhere I can think of and no one quiet has the answer for my problem.

I want this to be as simple as possible.

In the space where it asks “Twitter Site Tag” and expects my username, I want tobe able to place my username and then a hashtag.

So “user #tag”

This way every single post is tagged with the exact same tag.

I really can’t seem to find a solution that will allow me to add the same single hashtag to every post so when visitors click the twitter button, the hashtag is included.

Can you point me in the right direction or offer me some code or something. I see things talked about involving hashtags all over the place, but none that seem to allow a systemwide single hashtag to be set.

https://wordpress.org/plugins/jetpack/