Release yaml problem downloading artifacts

I have a successful build (yaml) and release (gui) pipeline in Azure pipelines. I'm trying to convert my release GUI version into yaml version. I know that I can get the snippet of yaml from GUI release version and I did. However, I'm missing something else I guess because I'm getting an error in the release about the drop not found.

I'm trying to deploy to Web App Service on Azure.

Any initial thoughts?

Starting: DownloadBuildArtifacts
==============================================================================
Task         : Download build artifacts
Description  : Download files that were saved as artifacts of a completed build
Version      : 0.206.0
Author       : Microsoft Corporation
Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/utility/download-build-artifacts
==============================================================================
Downloading artifacts for build: 64
##[error]Artifact drop not found for build 64. Please ensure you have published artifacts in any previous phases of the current build.
Finishing: DownloadBuildArtifacts

Build yaml

# ASP.NET
# Build and test ASP.NET projects.
# Add steps that publish symbols, save build artifacts, deploy, and more:
# https://docs.microsoft.com/azure/devops/pipelines/apps/aspnet/build-aspnet-4

trigger:
- master

pool: rspool


# ASP.NET
# Build and test ASP.NET projects.
# Add steps that publish symbols, save build artifacts, deploy, and more:
# https://docs.microsoft.com/azure/devops/pipelines/apps/aspnet/build-aspnet-4

trigger:
- master

pool: rspool
  

variables:
  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'

steps:
- task: NuGetToolInstaller@1

- task: NuGetCommand@2
  inputs:
    restoreSolution: '$(solution)'

- task: VSBuild@1
  inputs:
    solution: '$(solution)'
    msbuildArgs: '/p:DeployOnBuild=true /p:WebPublishMethod=Package /p:PackageAsSingleFile=true /p:SkipInvalidConfigurations=true /p:PackageLocation="$(build.artifactStagingDirectory)"'
    platform: '$(buildPlatform)'
    configuration: '$(buildConfiguration)'

- task: VSTest@2
  inputs:
    testSelector: 'testAssemblies'
    testAssemblyVer2: |
      **\UnitTestProject*.dll
      !**\*TestAdapter.dll
      !**\obj\**
    searchFolder: '$(System.DefaultWorkingDirectory)'

- task: PublishBuildArtifacts@1
  inputs:
    PathtoPublish: '$(Build.ArtifactStagingDirectory)'
    ArtifactName: 'drop'
    publishLocation: 'Container'

Release yaml

variables:
  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'
  Parameters.ConnectedServiceName: 'WorksFine'
  Parameters.WebAppKind: 'webApp'
  Parameters.WebAppName: 'mysolname'

steps:

- task: DownloadBuildArtifacts@0
  inputs:
    artifactName: 'drop'
    buildType: 'current'
    downloadType: 'single'
    downloadPath: '$(System.ArtifactsDirectory)'
- task: AzureRmWebAppDeployment@4
  displayName: 'Deploy Azure App Service'
  inputs:
    azureSubscription: '$(Parameters.ConnectedServiceName)'
    appType: '$(Parameters.WebAppKind)'
    WebAppName: '$(Parameters.WebAppName)'