I'm not in or associated with that Union but, what I could find is that they have some prerequisites that need to be met in order to be eligible to join.

According to their statutes :

"211 Rätt till medlemskap i förbundet har den som har avlagt ingenjörsexamen omfattande minst 180 högskolepoäng vid svensk högskola eller den som har likvärdig utländsk examen och har svensk anknytning. Förbundsstyrelsen får efter särskild prövning bevilja annan person "

English translation: "211 The right to membership of the association is granted to those who have completed an engineering degree of at least 180 credits at a Swedish university or to those who hold an equivalent foreign degree and are Swedish-affiliated. The Federal Administration may, after special examination, grant other person"

My interpretation of that clause; is that if you reside in Sweden and work here, you should be eligible to be a member. But that's not for me to decide.

They refer all questions to their contact form and welcome all questions regarding becoming a member, but ask that its done through the contact form. Could only find the contact form page in swedish.

Hope this helps.

https://www.sverigesingenjorer.se/hjalp-kontakt/kontakta-oss/

Edit: you of course also have to have an engineering degree minimum 180 swedish university points or equivalent.