Unable to download Xcode as iMac Os not compatible

HI there - I have just started developing apps and need to download Xcode. However, my iMac is mid-2011 and therefore I can't upgrade the OS beyond Sierra 10.12.6. Xcode is telling me that I have to have a later OS to download.

Any suggestions or is my iMac now just a heap of useless and obsolete junk?