Hi,
At 59 seconds into this [https://www.youtube.com/watch?v=vRZNXa1bozA|video] that battery type number for the Earbuds+ can be seen.
It’s a ICR1454S coin cell battery.
Searching online using the ''type number only'' gets results for an ICR1454 battery not the “1454S” .
I don’t know if they are the same or not but this [https://products.varta-microbattery.com/applications/mb_data/documents/sales_literature_varta/2018_05_HANDBOOK_CoinPower_en.pdf|Varta coin cell datasheet] (see p.32) gives the specifications for the ICR1454 battery. There is no mention of the ICR1454S. Perhaps it is a later type.
Check what type number is printed on the battery that you have and search online using the ''battery type number only'' to see if there are any suppliers.
Hopefully this is of some help.