thank you very much for sharing your question with the Wefugees Community!
There are several pages on the internet where you can look for jobs in Germany, some of them are especially for Blue Card Jobs in Germany. I will list some of them here for you:
1. www.research-in-germany.org is a website by the German Federal Ministry of Education and Research designed for researchers working in Germany. They inform about job and career opportunities as a researcher in Germany and under "Jobs&careers > find a job" they list various job portals especially for researchers. So this could be a good fit for you!
2. blue-card-jobs.com is a website where employers in Germany can directly post their job offers and candidates can apply. But on this job portal they do post all kinds of jobs, so they might not be research related. But you can check it out either way.
If you have more questions, f. e. example regarding the application for a Blue Card please don´t hesitate to ask!
All the best,