2 female students, looking for a place in Lisbon. We have around 500 euros total for a month. We will stay at least 2 months.

Hi, my name is Sema. My friend (female)and I are gonna be in Lisbon for around 2 and a half months starting at the end of July. We passed and Erasmus Internship test and we will be interning there. We are looking for a place to stay but we cant rent a room (still a plan b) bc she has a health problem. We wanna stay together and split the money so we have around 500 euros for an apartment. It can be a studio apartment or even in a dormitory. We don't know the place but it would be great to be in a safe and central place. Please let me know if you can recommend a good, clean and safe apartment. ( This might be a luxury so ı didn't say but ı would be really happy if there is a balcony, garden or some part with fresh air.)