Explanation:

https://docs.microsoft.com/en-us/azure/role-based-access-control/tutorial-custom-role-powershell Get-AzRoleDefinition -Name "Reader" | ConvertTo-Json
https://docs.microsoft.com/en-us/powershell/module/az.resources/get-azroledefinition?view=azps-5.9.0
https://docs.microsoft.com/en-us/azure/role-based-access-control/tutorial-custom-role-powershell
https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/convertto-json?view=powershell-7.1
https://docs.microsoft.com/en-us/powershell/module/azuread/get-azureaddirectoryrole?view=azureadps-2.0