Query regarding deploying infrastructure directly using bicep files under infra

[vaiddas]

I am trying to deploy the infrastructure using GitHub action and passing parameters in separate json file.

    - name: Deploy Bicep file
      uses: azure/arm-deploy@v1
      id: deploy
      with:
          subscriptionId: "xxxxx"
          scope: subscription
          region: 'xxxxx'
          template: infra/main.bicep
          parameters: infra/parameters.json
          deploymentName: xxxxxxx

I have a query:

1. Can I deploy resources using directly main.bicep and passing parameters?
2. I am using Service Principal to deploy the resources but I can see that some roles in main.bicep such as "openAiRoleUser" or "searchRoleUser" or "searchIndexDataContribRoleUser" have principalType: 'User'

I am using SP to deploy the resources so I have set principal ID of SP in my parameters.
But I get an error something like:

"message"
: 
"The PrincipalId 'xxxxxxx' has type 'ServicePrincipal' , which is different from specified PrinciaplType 'User'."

so either I need to change the main.bicep to have principalType: 'ServicePrincipal' or use "some user's principal ID" to deploy all resources.

I wanted to understand if I am not supposed to use SP to deploy the resources ?
if I can use both user id as well as Service Principal then why I am getting this error?
what would be the impact if I change the principalType: 'ServicePrincipal' and then deploy the roles? I tried and everything got deployed but I am not sure if that's the correct way.

Thanks.