The Swedish Migration Authority will not charge application fee for those who have been prevented from returning home due to Covid 19. However this will apply only to applications submitted by 18th May 2020. Full details may kindly be seen below:
https://lifos.migrationsverket.se/dokument?documentSummaryId=44330
https://www.migrationsverket.se/English/About-the-Migration-Agency/Coronavirus.html