If you are a national of a country with which Slovenia does not have a visa-free regime, you will need a visa or residence permit in addition to a valid travel document to enter Slovenia.
A visa is a permit to enter a country issued by the competent diplomatic and consular representation of the Republic of Slovenia abroad. A visa is also issued only for transit through the territory of the Republic of Slovenia.
You can only obtain a visa if you have a valid travel document, and the validity of the travel document must be at least 3 months longer than the validity of the visa.
The visa itself does not allow you to enter the country. If the facts that led to the visa being issued have changed, the border authorities may refuse entry and cancel the visa. A visa can also be cancelled if it is subsequently found that incorrect information was provided or material facts were withheld during the visa application process.
See more information: Ministry of Foreign Affairs.