From where you are trying to pull the code? If you are trying to pull the code for the first time then you need to clone the code for the first time so you can refer this link to checkout multiple repos from different code repository managers: https://learn.microsoft.com/en-us/azure/devops/pipelines/repos/multi-repo-checkout?view=azure-devops

I could also see you are using -script without any task it is good practice to use the task for such implementations for consistency.