Hello Jeison Arenhart De Bastiani,
Thanks for reaching out to Microsoft Community.
We're sorry for the inconvenience this has caused you. We understand how concerning this could be.
In this case, we regret to inform you that it's not recommended to buy a separate earbud if either one was lost. These wireless earbuds are paired with its charging case, and if one of these was lost or damaged then you need to purchase a whole replacement.
At this point, it would be best to get in touch with our Microsoft assisted support to check for further replacement options for your earbuds, if necessary. Here's how:
- Go to Contact Us - Microsoft Support and select Devices.
- Choose your preferred support method.
- Type in the problem you need help with.
- Look at any available solutions offered and select Contact Support.
For detailed instructions on how to contact our support via web browser, you might want to see this thread: click here. In any event the link won’t go through, try it on another browser.
I hope this helps.
All the best,
StevenK