There are plenty of jobs in .NET. So, you need to upgrade yourself to latest releases of .NET including .NET 5/6, Blazor, EF Core 6, Web API etc. Add Azure to your toolbelt. Everything is moving to Azure these days. That should keep you relevant to market.
If you're not learning this at your work, you can learn your own. Create smaller project yourself. Learn new products and write about them, share on communities like this. Attend webinars, conferences, and watch online trainings, certifications. Again, you will need to explore new things your own. There are plenty of free conferences, shows, webinars, podcasts happening here on C# Corner.
Here is one of the exciting conferences on Azure: https://azuresummit.live/
Become a certified developer associate.
https://globaltechconferences.com/
Cheers!