I have a process builder which I want to build to production, when I create a change set it says that this change set requires the "45.0" or later platform version, if it was a visualforce page I could change the api version, but I couldn't do that for the process builder, how can I accomplish that? The production runs in 44.0 api version and my sandbox in 45.0 api version.
Please refer to this article from salesforce Version error when uploading Change Set
You might just have to clone your change set and try deploying again.
Best Regards, Amit
After I had deployed a change set from a v53 sandbox to a v53 sandbox, Salesforce would not let me upload it to v52 production, even though all components were Apex classes with v52 or lower. I cloned the change set and then it was possible to upload it to v52 production. So cloning solved the problem for me. Sep 1, 2021 at 13:05
Hopefully you have deployed by now, but for future readers, I would suggest cloning the Process Builder to get a new version. I would expect the cloned version to have the latest API version.