Kobo US has a gift card offer right now for Father’s Day, through June 18. It’s buy $60 get $10 bonus, and seems to be pretty much like all the other recent similar offers. I tried to include the exact T&Cs in the screenshot at the top of the post, but they’re just too small to read, so here they are:
Offer Details
Limited time offer. Receive a bonus $10 eGift when you send a Kobo eGift of $60 or more. Offer good for one time only per customer. Offer starts June 11, 2024 12:01 AM EDT and ends June 18, 2024 11:59 PM EDT. You will require a Kobo user account to redeem or send an eGift. Bonus eGift will be emailed to the purchasers Kobo account on file within 72 hours after purchasing the eGift. Rakuten Kobo Inc. reserves the right to change or end this offer at any time without notice.
It does seem, however, that Father doesn’t do as well as Mother 
– the Mother’s Day offer only made you buy $50 to get the $10 bonus. (Or, I suppose that could mean Father will do better, since he’ll get a bigger gift card…)
I suspect that there will be similar offers at other Kobo stores (UK, Canada, etc.), but don’t have time to check right now.
Anyway, here’s the link to the Kobo US gift card page, and the offer just shows up for me as a banner ad, a little ways down in the page.