AWS lambda create-function accepts only one environment variable

The other option is to put the environment variables in a json file (ex: environment.json) and use that instead... and: % aws lambda update-function-configuration --function-name MyLambda --environment file://environment.json

... or ... you could also use the file://environment.json command in your create-lambda statement

You should try with Variables="{KeyName1=string,KeyName2=string}"