try expanding the env var elsewhere

action.yml

@@ -5,7 +5,6 @@ inputs:
   tgf-path:
     description: Installs the TGF binary to this folder. The folder will not be added to the PATH.
     required: false
-    default: ${{ runner.os == 'Windows' && '${env:LocalAppData}\Microsoft\WindowsApps' || '/usr/local/bin' }}
   ref:
     description: The ref to use to run the install script.
     default: ${{ github.action_ref }}
@@ -19,15 +18,15 @@ runs:
     if: runner.os != 'Windows'
     shell: bash
     env:
-      TGF_PATH: ${{ inputs.tgf-path }}
+      TGF_PATH: ${{ inputs.tgf-path || '/usr/local/bin' }}
       VERSION: ${{ inputs.ref }}
     run: curl "https://raw.githubusercontent.com/coveooss/tgf/${VERSION}/get-latest-tgf.sh" | bash
 
   - name: Install TGF (windows)
     if: runner.os == 'Windows'
     shell: pwsh
     env:
-      TGF_PATH: ${{ inputs.tgf-path }}
+      TGF_PATH: ${{ inputs.tgf-path || '${env:LocalAppData}\Microsoft\WindowsApps' }}
       VERSION: ${{ inputs.ref }}
     run: |
       echo ${env:TGF_PATH}