Hello. What is your goal? What is the other device you want to do the shortcut? Companion module ui is loaded into browser. So you can do it from any pc browser/mobile phone browser by using the ip address from your pc in your lan following by :8000/tablet

Ok so you will use the streamdeck. Yes this is possible by using vmix companion module. I assume that you allready know how to create a new button in vmix companion module. Create the button and for any action you need select press actions-->vmix-->vmix: Scripting - Run custom command and in the field it gives you see here vmixapi.com
It gives you the commands in the format for companion action i said. For example for overlay1 an input https://vmixapi.com/?function=OverlayInput1 you have to enter OverlayInput1 Input=My input
There also some commands inside the vmix companion module but for exactly name-command see the site and do your shortcuts as you need

So you need a way to copy-paste all your shortcuts at once and any shortcut by using different button? I dont think this is possible
Companion and any other 3rd party program is external program and not tied inside in vmix. So the way they work with vmix is the xml file. If we open in a notepad a .vmix file and search for the shortcuts we can see that the way are stored-understand them the program is a bit way different and dont directly compatible copy-paste with other programs.

Vmix can communicate the api with external programms with 2 kinds. One is the url call-->http request and the other is tcp api request. If you go to vmix settings-->webcontroller you will see the last option that says TCP API.
If you go to companion ui-->connections and press the vmix module we see this "Connection Info Companion uses vMix's TCP port (8099). Do NOT enter your Web Controller port, and ensure that the Web Controller is NOT set to 8099 as that will cause a conflict."
So the developer of the module decided to connect with vmix via the tcp protocol. So the way i say to you before is actually the URL call you mention that is transformed and send as tcp. I dont know if the vmix module offers a way to put your shortcut like http://127.0.0.1:8088/api/?Function= but it is same thing

You`re right/. I discovered now (better late from never haha) that if in companion vmix module we use the action vmix: General - Keypress and then put as value the keyboard letter we assigned in the vmix for a shortcut it will do the action like we press the keyboard! So the only thing we need to do to transfer the vmix keyboard shortcuts over companion/streamdeck is to write the general-keypress letter and it will act as our keyboard!