Starting with v5.11.0, Insomnia users can now authenticate using the OAuth 1.0 authentication framework!
OAuth 1.0 support was an extremely popular request so I'm proud to finally announce that it's finished. In fact, it was the most popular issue on GitHub for a long time. I'd like to give a huge thanks to besolov who stepped up and provided then initial implementation, and to EpocDotFr as well for doing initial testing.
Since OAuth is a fairly complicated framework, please report any bugs or issues you run into on GitHub.