There's 1 left shifter on Amazon....

SRAM Force eTap AXS Shift/Brake System Black/Grey, Left/Front, Flat Mount https://www.amazon.com/dp/B07TW3TC97/ref=cm_sw_r_apan_glt_fabc_3BTYC1EVHXDS94P70JEC

I bought one there today and am scouring the web for the right one!! At least with Amazon you can return thru 1/31 in case it doesn't work out.

I think I have a GRX 1x pieced together but everything's so damn expensive I think it's worth the few extra hundred to go Rival/force AXS mullet.