displaying default value for encounterProvider in openmrs form builder

I’m trying to set a default value for the Encounter Provider dropdown in my OpenMRS form builder.

What I’d like is for the dropdown to automatically show the currently logged-in provider by default, instead of starting empty.

Here’s what I have so far (without any edits):

{ "type": "encounterProvider", "label": "Consultant / Provider", "id": "consultant/Provider", "required": "true", "questionOptions": { "concept": "984AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", "rendering": "select" } },

i have tried many solutions eg:

{ "type": "obs", "label": "Consultant / Provider", "id": "providerName", "required": "true", "questionOptions": { "concept": "166511AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", "rendering": "text" }, "default": "{{sessionContext.currentProvider.person.display}}", "readonly": "true" }

this:

{ "type": "obs", "label": "Consultant / Provider", "id": "providerName", "required": "true", "questionOptions": { "concept": "166511AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", "rendering": "text", "calculate": { "calculateExpression": "'{{user.person.preferredName.display}}' || '{{sessionContext.currentProvider.person.display}}' || 'Current User'" } }, "readonly": "true" }

when I try these, the dropdown just shows blank.

So my question is: is what I’m trying to do even possible in the OpenMRS form builder? And if yes, how can I achieve it?