Hi @alexmigf
Thank you for sharing the pre-release version with us.
Unfortunately this version throws the same error.
We also noticed you’re still working on this issue:
Commit deb6a3c from yesterday: https://github.com/wpovernight/woocommerce-pdf-invoices-packing-slips/commit/deb6a3ce05d5ed86bd8fbfd4a2847d0f25518159
Can we suggest something to check?
We think the issue might be related to the WooCommerce versions you are supporting.
According to the comment block in the main plugin file, you support WooCommerce 3.3 or newer.
WC requires at least: 3.3
We are using WooCommerce version 4.5.3
It looks like the woocommerce_register_additional_checkout_field function is not yet available in these versions.
There might be an older related function you could use, we don’t know that.
If not, you might consider to bump the minimum WooCommerce version for this project.
Maybe we’re completely wrong, but we thought it is worth checking out.
Thanks!
