@yorex Based on other successful applicants’ feedback here, you also need to show evidences which are not just references. Depending on which optimal criteria you select for yourself the evidences you need to show will vary.
Some of the evidences that you can show are news clippings, speaking or participating in a panel at a conference, open source project participation, etc.
You have mentioned that you have some public side projects on your GitHub but make sure that if you are showing them as evidences then you show the positive effect those projects had in the tech sector by providing numbers (quant analysis such as likes, number of forks, your contribution through commits, etc.)
I would suggest you to look at the successful endorsement cases that applicants have provided here to get some idea about how you could approach your endorsement application.
In case it helps, I have shared my evidences’ here: This is how I got my Endorsement for Global Talent Visa under Exceptional Talent Route (AI/ML Researcher)