First thing in your setup at very first you missed two steps
in which it's asking about the docker registry and username & authentication.
If you will pass the detail you won't face any issue and secret will get created automatically.
You have to set the value for pull secret to true
createPullSecret: true
pull seceret is used by Kubernetes config when you have to fetch the container (docker) image from the private container repository for example private docker repository.
If your config pull already exist but you have not created it you can create it manually by providing a few details
kubectl create secret docker-registry my-pull-secret --docker-server=[REGISTRY_URL] --docker-username=[REGISTRY_USERNAME] --docker-password=[REGISTRY_PASSWORD] --docker-email=[YOUR_EMAIL]
Read more at : https://devspace.cloud/docs/v3.5.18/image-building/registries/pull-secrets
There is same issue reported previously : https://github.com/loft-sh/devspace/issues/1317