In detail Communication option for accounts and contacts, you can find the communication option Web - after the link is added to it you will be able to click it. To add this logic to your field check the code of this detail in OOB mobile application and mimic it for your field.
I have seen this field, but in the advanced settings it is hidden from me as it is a out of the box field. I cannot find it in any lead mobile page or lead edit page v2.
If you have source code for this, please provide me so that I can implement that on my field.
Check MobileAccountCommunicationModelConfig schema or simular schema for contact section.
I have checked all the schemas related to account and contact, but could not find the definition for that "Web" field which is clickable in mobile.
I have checked the MobileAccountCommunicationModelConfig also but could not find anything.