The Embasy of Ireland in Vilnius processes visa applications for entry into Ireland from Lithuania.
Please refer to the website of the Irish Immigration Service for information on visas for entry into Ireland here: Home - Immigration Service Delivery (irishimmigration.ie)
If you are unsure as to whether you require a visa/preclearance to enter Ireland you can check here by entering your nationality.
Please be aware that all travellers arriving into Ireland must continue to comply fully with measures required by law including producing proof of vaccination, recovery from Covid-19 or a negative PCR test. Full information is available here.