Welcome :-). Firstly I am moving this to the Power Automate Flows where it should have gone so it's in the correct place.
I would really need to see the actual flow. Having the pseudo steps is nice, but it's not enough to help you. There are multiple Triggers that can do what you are saying in SharePoint, so seeing the exact one is important.
If it says it doesn't see it, then you are pointing to the wrong place, honest, it's just that simple.
Showing Simple Sample, This is what I need you to do (its listed below).
Here you can see I have a simple flow when a File is created properties only.
I literally put all 3 flavors or Get file metadata and content and you can see they all work.
So for Get File Content and Get File Metadata, you need to use the one named Identifier.
When I first try to add it to the Get File Metadata, all I see is the trigger properties, and I have to click Show 60 more. Then scroll down and you will see it, its not in alph order oddly or at least not fully so just go slow until you see it, then when you add it looks like the below
Then for Get File Content with Path
I simply use the Dynamic Full Path property of the Trigger
As you can see all of mine worked without issue.
So now I want you to build a flow just like mine above. except we are purposely NOT going to create a new one ... exactly, as I want to use your current trigger as is.
1. Turn off your current flow we don't want it on
2. Do a Save As on your current flow, as I do not want your trigger to change in any way
3. Delete everything below the trigger.
4. Add the next 3 actions, just like mine.
Populate the fields just like I have and run it in Test mode within the Editor. Once its running in test most, drop a file and I will bet that it works just fine.
Which if the above does, that says you are making a mistake with what you are doing in your other flow, which is why the Next Steps are important
Next Steps
1. Go into a Flow that Failed, do this via the Details page of the flow and pick a run
2. Provide Screen shots of the Flow up until it fails (after that doesn't matter)
3. Have the actions opened, showing the Inputs and outputs
4. We want to verify visually that the Incoming data from the Trigger, is what you are passing around, as right now I am not even sure where in the flow exactly this step is failing, so its possible you have unintentionally broken the context of the trigger data or are just... accidentally pointing to the wrong Library
This is how we will find it
Bring that back, or if you do the test and mine works, then you go Oh.. now I see. and it resolves your Issue, please Mark the answer as such and maybe a like.
Thanks!