TypeError: (intermediate value).run is not a function error in serverless-finch client deploy

Question

I am using serverless-finch plugin for serverless client deploy. My configuration is as below:

service: myservice

frameworkVersion: '3'

plugins:
  - serverless-finch
custom:
  client:
    bucketName: xyz.com  
    distributionFolder: client/xyz.com/dist/browser/
    indexDocument: index.html
    errorDocument: index.html

When I am trying to deploy my client (Angular 6) using sls client deploy , I am getting this error:

Warning: Invalid configuration encountered
  at 'provider.lambdaHashingVersion': must be equal to one of the allowed values [20200924, 20201221]

Learn more about configuration validation here: http://slss.io/configuration-validation
This deployment will:
- Upload all files from 'client/xyz.com/dist/browser/' to bucket 'xyz.com' undefined
- Set (and overwrite) bucket 'xyz.com' configuration
- Set (and overwrite) bucket 'xyz.com' bucket policy
- Set (and overwrite) bucket 'xyz.com' CORS policy
Environment: darwin, node 12.13.0, framework 3.2.1, plugin 6.0.0, SDK 4.3.1
Docs:        docs.serverless.com
Support:     forum.serverless.com
Bugs:        github.com/serverless/serverless/issues

Error:
TypeError: (intermediate value).run is not a function

2 deprecations found: run 'serverless doctor' for more details

Can't get any clue from this brief error description:

Error:
    TypeError: (intermediate value).run is not a function

I have build my angular project using sudo ng build --prod and dist folder is ok, I can run it locally without any problem. Manual upload dist folder to s3 is also working perfectly. But can't deploy it using the serverless client deploy command.

Can anybody help?