There are several ways to delete a version of a lambda function. All the followings have the same effect. See the manual for details.

With the function name followed by the version

aws lambda delete-function --function-name ${FUNCTION_NAME}:${VERSION}

Example:

aws lambda delete-function --function-name my-function:1

With the function name and the qualifier option

aws lambda delete-function --function-name ${FUNCTION_NAME} --qualifier ${VERSION}

Example:

aws lambda delete-function --function-name my-function --qualifier 1

aws lambda delete-function --function-name ${FUNCTION_ARN}:${VERSION}

Example:

aws lambda delete-function --function-name arn:aws:lambda:us-west-2:123456789012:function:my-function:1

aws lambda delete-function --function-name ${FUNCTION_ARN} --qualifier ${VERSION}

Example:

aws lambda delete-function --function-name arn:aws:lambda:us-west-2:123456789012:function:my-function --qualifier 1