You can connect the Align A10 receiver A6B to the Microbeast using the A Bus.
The Microbeast firmware has to be V5.
Just connect a wire between the receiver A Bus and the Microbeast's ELE/DI1 port.
No other connection is required between the receiver and Microbeast.
Make the Microbeast do a auto receiver type scan through a PC/Table (with wired or BT dongle), or
press and hold the Beast's button while you power it up. The status LED should be purple after the scan.
Read the V5 manual on the detailed procedure on channel assignment.
As for the throttle signal to the ESC, it will be from the Ch3 of the receiver.
Channel assignment for the A10 receiver:
Prior to channel assignment setting on Beast, you need to set up A10's throttle hold function,
and put the A10 at throttle hold.
When assigning pitch channel, move the throttle stick (A10 remains at throttle hold).
When assigning throttle channel, flip the throttle switch (don't touch the throttle stick).