How can I change the version of a Flexipage through SFDX?

Question

I am trying to deploy a flexipage that was modified in our repo, but the target sandbox is giving me this error:

Property 'itemInstances' not valid in version 47.0

Based on what I could find in search engine results, itemInstances is something allowed in newer API versions. So it seems like either SFDX is trying to deploy the flexipage with the version number set to 47, or the target org is somehow set to version 47 and won't accept these changes for a newer API version.

What I haven't been able to figure out is how do I tell SFDX to deploy a certain API version for the flexipage? I am a developer and more familiar with deploying Apex code, so if this were a class I would update the meta file's XML to have an updated version number, like so:

<?xml version="1.0" encoding="UTF-8"?>
    <ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>49.0</apiVersion>
    <status>Active</status>
</ApexClass>

But when I look at the flexipage meta XML file, that tag doesn't exist. Do I just need to add it? Or is there a different way that is recommended?

Answer 1

Change the target API version in your sfdx-project.json file, for example:

{
  "packageDirectories": [
    ...
  ],
  "sourceApiVersion": "48.0"
}