Sorry for the delay in getting back to this. The easiest (though awkward) way to get your company ID is the following:
* Go to the
Apply Button configuration tool
* Type in your company name and select it from the drop down
* Add an email address and title for the 'position' you're creating (this can all be fake)
* Hit the "Get Code" button
In the bottom textbox, you'll see the code for the Apply button. In there will be a line like data-companyid="365848" . That's your company ID.
Sorry it's so confusing. There used to be a way to fetch the ID from your actual company page on LinkedIn, but it seems like they removed that.