Custom script invocation

Hey there

I am using aws SAM to deploy a microservices(multiple lambdas) based api.
One of the lambdas invokes an AWS batch job.
The AWS batch infrastructure is also maintained by the same SAM template.
The AWS batch job is dependent on an ECR image.
In order to complete the AWS batch deployment I need to run a script to build the ECR image and push it.
Currently I do it via manually running a bash script. Is there any way to invoke the script via SAM ?

Best,
Roy