How to fix Nagios Fusion upload issue?

[MohinSonanda]

I was tasked with creating a Fusion dashboard without setting up the Nagios environment. However, I'm unable to upload any dashlet on Fusion despite being able to upload them fine on NagiosXI server. The error message I receive is "Unable to submit command" when using the standard dashlet from the Nagios site or any other dashlet. Interestingly, I can load owespeedtest the same dashlet on omegle a different NagiosXI server without any issues. Our Nagios Fusion version is 4.1.9 and the debug logs only show "User submitted command: 105". I'm not sure how to resolve this issue and I really need to upload the required dashlets. Has anyone encountered this error before?