Does the OnePlus 6 have eSIM? No

No, the OnePlus 6 has no eSIM, so it cannot take a travel eSIM. You need a phone that supports eSIM, or a physical SIM card at your destination.

What to know about the OnePlus 6

Two nano-SIM slots and no eSIM. To get data abroad, see what to do when your phone has no eSIM.

Two minutes on the phone itself settles it, whichever version you have.

Dial *#06#
Open the phone app and dial *#06#. If a number labelled EID appears, your phone supports eSIM.
On Android
Go to Settings, then Network and internet, then SIMs. If you can add an eSIM or download a SIM, it supports eSIM.
Check it is unlocked
A phone bought from a carrier on contract may be locked to it. Ask your carrier, or look for a Carrier Lock line in your settings that says No SIM restrictions.

Share a companion's travel eSIM, buy a local SIM or roam: which one fits your trip.

Every OnePlus model we have checked, with the versions that leave eSIM out.

The 30-second check for any phone: the EID, and whether it is unlocked.