Can you lock minecarts to be not able to move in Bedrock?

Make a repeating always active command block with the command:

tp @e[type=minecart,r=2,c=1,x=5,y=10,z=15] 5 10 15

Replace 5 with the X coord, 10 with the Y, and 15 with the Z.

Let me know how that works for you, if it doesn’t work how you’d like I might have another idea.

I think the easiest way would to be to put the cart on top of a hopper with a rail in between, and then to break the rail. For parkour this would be an issue because you could land on the hopper. I dont think it is possible to get a minecart to simply float in the air. With the hopper, it will still move a little but not as much as if on a block or on a rail.