Creating 'clickable' Phone numbers in Lists

[Jen_C2405]

I have created an MS list that contains a phone # column that I would like to be a 'clickable' link that would prompt to dial the number.  

I have edited the column in SPO and added the following JSON code.  This makes the links live in SPO, and the desktop version of Lists, but does not work on iPhone.  It opens up in an editor when i click on the number.  

Is this a bug in the lists app, or does anyone know the fix for this?   I have also tried replacing TEL: with callto:  with no luck. 

{
"$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
"elmType": "a",
"txtContent": "@currentField",
"attributes": {
"target": "_blank",
"href": "='tel:' + @currentField"
}
}

[#2]

Same issue here. Any resolve?

[#3]

@Jen_C2405 

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "a",
  "txtContent": "@currentField",
  "attributes": {
    "href": "='tel:' + @currentField"
  }
}

[#4]

@maurice_wijman 

Thank you for this solution. However, I would am trying to add phone numbers with extensions (optional) as well so wondering if there is any way around to this. 

I am not a tech guy/coder so couldn't come up with my version of code testing before asking you. 

Thank you so much for your help