How to use env variable in target?

Is it possible to use an env variable in target?
```
env:
SRV_HOME: /home/ubuntu

steps:
- uses: actions/download-artifact@v2
with:
name: app-build

- name: Upload
uses: appleboy/scp-action@master
with:
host: ${{ matrix.server.ip }}
username: ${{ matrix.server.username }}
key: ${{ secrets.SSH_KEY }}
port: ${{ matrix.server.port }}
source: ${{ github.sha }}.tar.gz
overwrite: true
target: $SRV_HOME/$APP/artifacts
```
I can't seem to get it working and debug messages are obscure:
```
tar all files into /tmp/1238089582/NFthDUKQxA.tar
scp file to server.
create folder $SRV_HOME/$APP/artifacts
drone-scp error: Process exited with status 1
drone-scp rollback: remove all target tmp file
remove file NFthDUKQxA.tar
2023/01/03 15:23:57 Process exited with status 1
```

Start by reproducing the workflow shown in the issue, including the env block and the target value using $SRV_HOME/$APP. Read the action's handling of the target input and compare the generated remote folder command with the expected expanded path. Done means the documented workflow reliably creates the intended target directory or clearly reports the supported syntax.

Written by the indexing model from the issue text.