There is an old 'Add shipping phone' plugin.

https://www.zen-cart.com/downloads.php?do=file&id=1100

This adds a new phone field to shipping address which I think is a good idea because the sender's phone number might not be appropriate.

However it was last updated for 155 - but it might lead you in the right direction.

(I've always meant to check this out because it would be useful for myself but have never got around to it)