Convert input text into duration values with script on Google Sheets

I'm setting up a sheet to help coworkers keep track of their appointments. For now the only way to get those times is to copy-paste the numbers from a different program used to track the info. The information pasted on the sheets shows the appointment lengths as X h X m (eg. 2 h 15 min).

The issue is the sheet will view this as text rather than a time value so I can't use the numbers to calculate anything. I found an onEdit script that will convert the text into the time values, however it requires me to go through and edit each cell (add or remove a space) before it will convert the text.

I've already set up a few scripts on this sheet so I'm hoping I can replace the onEdit script with one that can be run by clicking a button like the other scripts I have. The data will be pasted into same range so setting the range of where to convert will always match up.

Script from other answer:

function onEdit(e) {  var value = e.value;  if (typeof value == 'string') {    var match = value.match(/(\d+) ?h/i);    var hours = match ? match[1] : 0;    match = value.match(/(\d+) ?m/i);    var minutes = match ? match[1] : 0;    match = value.match(/(\d+) ?s/i);    var seconds = match ? match[1] : 0;        if (hours || minutes || seconds) {      var duration = hours/24 + minutes/1440 + seconds/86400;      e.range.setValue(duration).setNumberFormat('[h]"h "m"m "s"s"');    }  }}

edit: Changed my wording a bit to make it more clear that I want to replace the onEdit script.

edit 2: I've tried doing this to the script but it does not work:

function setDuration(){  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();  var value = sheet.getRange("C45:C80");  if (typeof value == 'string') {    var match = value.match(/(\d+) ?h/i);    var hours = match ? match[1] : 0;    match = value.match(/(\d+) ?m/i);    var minutes = match ? match[1] : 0;    match = value.match(/(\d+) ?s/i);    var seconds = match ? match[1] : 0;        if (hours || minutes || seconds) {      var duration = hours/24 + minutes/1440 + seconds/86400;      range.setValue(duration).setNumberFormat('[h]"h "m"m "s"s"');    }  }}

I'm not too familiar with how onEdit scripts work so I'm not sure how to properly convert the script.