How can I add a validation regex to a Kontent slug element using the Kontent JS Management SDK

Hi there :) I'm struggling to add a validation regex to the URL Slug in my Content Type. I can set it manually e.g.

But I want to set it programmatically using the JS Management SDK. This is one of the things I have tried...

    const mod: ContentTypeModels.IModifyContentTypeData[] = [
        {
            op: 'addInto',
            path: '/elements/codename:page_url',
            value: {
                validation_regex: {
                    regex: '^[a-zA-Z-/]{1,60}$',
                    flags: 'i',
                    validation_message: 'URL slug must only contain (English/Latin) characters, forward slashes and hyphens',
                    is_active: true,
                },
            },
        },
    ]

That gives me the error >> Invalid operation with index '0': Unexpected path part 'codename:page_url'

In the hope that the problem is just with the path I have tried several other permutations, without success.

Is what I want possible in place i.e. without deleting and re-adding the element? And if so how?

The addInto operation is for adding new elements, so if there is no url slug element you can add a new one and specify the regular expression:

[
  {    
    "op": "addInto",    
    "path": "/elements",    
    "value":{    
    "depends_on": {    
      "element": {    
        "id": "d395c03d-2b20-4631-adc6-bc4cd9c88b0b"    
      }    
    },    
    "validation_regex": {    
      "regex": "^[a-zA-Z-/]{1,60}$",    
      "flags": "i",    
      "validation_message": "URL slug must only contain (English/Latin) characters, forward slashes and hyphens",    
      "is_active": true    
    },    
    "name": "some_slug",    
    "guidelines": null,    
    "is_required": false,    
    "type": "url_slug",    
    "codename": "some_slug"    
  }    
]

For updating just regex of existing url slug element you need to use the replace operation instead:

[
  {
    "op": "replace",
    "path": "/elements/codename:some_type/validation_regex",
    "value":{
      "regex": "^[a-zA-Z-/]{1,60}$",
      "flags": "i",
      "validation_message": "URL slug must only contain (English/Latin) characters, forward slashes and hyphens",
       "is_active": true
    }
  }
]

You can find more info in our API reference -> https://kontent.ai/learn/reference/management-api-v2/#operation/modify-a-content-type