I asked for gizmo to be introduced in the site, the request got rejected, but with no reason, it's fine if it gets rejected, but no reason? that sucks :/

Most likely due to inadequate information provided. You would need to submit a run that you have record of you doing the run, and a proper explanation and description of the game and what the speedruns are/could be like. Also there does not need to be a reason given for the rejection, if a reason is provided there is usually a specific reason as to why. But seeing as no reason was given tells me it was a poor effort for a submission in the first place.

You can always try and submit it again with a better recorded run, as well as better information about the game and the speedruns.

thank you! :)