Context.
In specific invoices we are filling in the References and Notes, because we need to easily search them after let's say a week.
In the reference we input the room number, while in the notes we input the name/surname.

Blocker.
When we need to search for that particular invoice, we can only input a numeric value in the search window in the app.

Request.
To be able to insert also letters, so to use the full keyboard, therefore to search also for the notes field.