Generally speaking, an applicant could be refused a visa if he or she doesn't meet the requirements for admission or entry under that nation's immigration laws. The European Commission explained an ETIAS authorization isn't the very same as a visa and will be a lot simpler to obtain. For this reason, you won't require an ETIAS authorization.
You can receive the ETIAS online. The travel authorization is going to be attached to a particular passport and will be non-transferable. If you intend to stay for a lengthier period, you will want to submit an application for a visa.