Every published report, including the official list of Trump's invites to his event, have indicated that Trump did not invite DeSantis to the event, by choice of Trump. Local TV reporters in Florida hypothesized that DeSantis could call Trump's bluff, and crash the event, but ultimately reported that DeSantis had chosen to just pursue other options for the evening.
So every indication is that is exactly what happened, and that is at this point considered to be the final explanation of events. However, if you have any other source that claims that is not what happened, you should present it now, as everyone would like to know for sure, but so far 100% of the evidence indicates Trump chose not to invite DeSantis.
And what about Mega Deep State donors pushing DeSantis to fend off Trump?