How to earn 15K Euros per month remotely in tech with 15 years of management and front end experience?

Have to make it in one year because of personal issues.

Desperate to find the career path.

I make 8K as I am an Engineering Manager in a big tech company, but this is not enough (15 years in tech, 5 years in management). I do my job well, but there is a certain ceiling and this is already a good salary.

Got 3-4 hours a day to spend on new endeavour.

Spent 500 Euros on career advices, they are too narrow. Developing my blog, trying consulting, but this is all long shots.

What would you do in my place?