whether · conjunction /ˈweð.ər/Full view
B1 used especially in reporting questions and when expressing doubt to mean if
Dictionary examples:

I wasn't sure whether you'd like it.

She asked me whether I was interested in working for her.

I doubt whether it'll work.

It all depends on whether or not she's got the time.

Learner example:

It's very expensive and I'm so broke that I don't know whether I can afford to buy one. (Preliminary English Test; B1; French)

whether... or
B1 used to talk about a choice between two or more possibilities
Dictionary examples:

I'm going, whether she likes it or not.

Someone's got to tell her, whether it's you or me.

Let's face it - you're going to be late whether you go by bus or train.

Learner example:

I don't know whether to stay or to go. (Preliminary English Test; B1; Spanish)

Cambridge University Press