Hi Elno welcome aboard Filipino UK
Concerning your question, based solely on the information shared, your Fiancee needs to secure Austrian naturalisation to enable your settlement there as husband.
It is normally possible to apply for Austrian citizenship by naturalization after 10 years of continuous residence in Austria. However, do be aware that Austria has some restictive rules on dual citizenship so it would require some research to find best option.
Austria does have a number of options so it's best to do some research based on your and your Fiancee's own personal circumstances.
Of course it may be possible for you to secure a visit visa, although I understand this is not what you specifically require.
Good luck