Can someone how to change the username or it is possible to change it?
Due to how discourse stores data only the admins can after you make a certain number of posts or have had an account for x number of days you can not change your user name. Admins can for you upon request so if you wish for your username to be changed feel free to DM me the new name you wish to use.
By any chance, would you add the ability to change our username anytime?
Also who should I DM with and how to do?
As explained above the reason why this cant be done is due to how the discourse framework handles its data. The best we can do is increase some of the duration and limits but this is ill advised by their best practices.
Click on my name or avatar. You should then see a small window pop up with a blue button that says message.