Codes U0073, U0123, U0124, U0126 and U0293

U codes are communication buss codes, no relation to the gas cap being off. The cap would have set a P code for an EVAP problem.
The codes you have are all present with a failure in a single module, that is the communication from the electronic brake control module. It gets information from other sensors and uses that to determine the braking and traction control dynamics of the car. These codes will set if there is longer than a three second communications issue. To determine which are is the actual problem will require scanning with a dealer level tool that can do more than just read the codes.

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

With that tool you can check each of the modules involved and see which one shows errors. From there it depends on which item is the problem as to whether it's a DIY repair or if it will require parts or programming at the dealership level.
The image shows the affected modules and the data connections. Those cannot be tested without specialized equipment like an oscilloscope and bidirectional scan tool. A common failure item in the system is the lateral accelerometer and yaw rate module. That is mounted under the center console just about straight down from the radio. However to get to it requires removal of multiple interior components. As such I wouldn't try to repair anything until you have a clear idea of what the failure is. Even a loose or corroded wire could cause this issue.