I use notebooks as part of the asset bundle deployment to conduct a lot of dynamic configurations based upon the workspace being deployed to (ex. Development, Test, Production).  In conjunction, I developed a helper Python library with a number of functions that are used with administrative tasks.  Attached is the one I created for adding schema permissions.

from typing import Tuple
import re

def addSchemaPermissions(schemaName: str, principal: str, permissionList: str, clearAll: bool) -> Tuple[bool, str]:

    try:
        if clearAll:
            spark.sql(f"REVOKE ALL PRIVILEGES ON SCHEMA {schemaName} FROM `{principal}`")

        spark.sql(f"GRANT {permissionList} ON SCHEMA {schemaName} TO `{principal}`")
        return True, ""
    
    except Exception as e:
        fullErrorMessage = str(e)

        # Try to extract the Databricks error class and readable message
        errorClassMatch = re.search(r"ErrorClass=([A-Z_\.]+)", fullErrorMessage)
        mainMessageMatch = re.search(r"] (.+?)\\n", fullErrorMessage)

        errorClass = errorClassMatch.group(1) if errorClassMatch else "Unknown Error"
        mainMessage = mainMessageMatch.group(1) if mainMessageMatch else fullErrorMessage.splitlines()[0]

        return False, f"{errorClass}: {mainMessage}"

success, errorMessage = addSchemaPermissions('your_catalog_name.your_schema_name', 'Your Principal Name', 'USE SCHEMA, SELECT', True)

if not success:
    print(f"Failed to update schema permissions: {errorMessage}")