Thank you Juanillor for the videos. They are informative but unfortunately not consistent, so I think we will still need more information.
In the first video (#8717) we can see that you have the throttle and steering channels defined correctly. This is very good. It's true as Rad says the throttle channel is reversed (invertir el canal del gas). But this is not necessarily a problem. The main thing is that when you move the stick forward OP Config says "Forward," which it does.
In the second video (#8718) we can see that the TCB thinks it is permitting you to move forward, reverse, and in neutral turn. Of course I don't know if that is actually what is happening on your model, maybe your narrative will say and if so Rad can understand that.
Now in the third video (#8719) we have the inconsistency. You are able to move forward and backwards, but you are unable to initiate a neutral turn. This is inconsistent with the second video (#8718) where we
do see neutral turns, although we don't see what stick movements cause them. Either you disabled neutral turns or made a configuration change we don't know about between video 8718 and 8719, or else you were using a different stick combination that I also don't know about.
Also without being able to see the model I can't tell where actually the problem occurs.
However I am certain we will fix this eventually with Rad's help.
Another question, can you confirm you have put your XCar 45 ESCs into Crawler Mode?
The Wiki describes how. If correct the LED on the ESC will be solid (not blinking).