Just to set expectations... Don't count on an SDK for the mini 5P (or mini 4P, mini 3P,
Air 3/3S,
Mavic 3 series, Mavic 4 series, and I'm sure a few others I've missed)
EVER being released.
This has been a sore point in the user community now for several years. DJI changed their product strategy years ago, deciding to provide waypoint functionality directly through DJI Fly, wrecking Litchi's entire business model.
Litchi is a much much better, more capable, and feature-rich waypoint solution, but DJI decided to stop supporting them and other 3rd parties in the DJI ecosystem.
For now, the DJI Fly waypoint functionality is "good enough" for most applications, but lacks some useful functionality that Litchi provided.
And to be absolutely accurate, there was an SDK for the Mini 3P, but it was a crippled version that only supports "Virtual Stick" operation, which requires a good, solid connection with the RC at all times to work. Litchi was not updated to support this SDK, instead Litchi developed a new app, "Litchi Pilot", which sucked worse than a Vegas street prostitute 40 years into her career. Don't know if LP ever got off the ground from beta.