Seeking Currency API for .NET Microservice Project

Hi devs👋

I’ve started what might be my most challenging pet project yet😎:
🔥Currency Dashboard with:

• ASP.NET Core backend
• Microservice architecture
• JWT Auth
• SignalR (for real-time updates)

I`m gonna use an external api to get information about currencies. Which free API would you recommend?
I bet I'll make more posts about my pet project soon✨.