I think that you should check out this TI Design ( TIDA-00409 ). It should show how you can interface with the modulator without the SMA connectors, however you should note that in this design the modulator is being interfaced with the DAC38J84.
The TSW38J84 is designed in Cadence Allegro. The design source files can be found in the Design Files section of TIDA-00409.
Altium can import those files using the Import Wizard. Please see the following guidance here: