EU students don't pay tuition fees for university in Denmark. Non-EU students have to pay tuition fees to study in Sweden.
Sweden accepts the IB Diploma NOT the IB Certificates for university admission.
Admission to Swedish higher education is organised by the educational institutions themselves. To be admitted to a higher education programme, you first need to contact the institution that offers the programme. They can inform you of exactly which admission requirements apply to the programme of your choice.
Finalise the application plan to understand your deadlines.
Submit the application well in advance of the deadline. The deadlines are published on the website of the university.
Wait for your admission decision. Usually, you will receive it via email.