Converting .csv to .fsn for tree input?

I’m trying to create a tree using this Qiime script: http://qiime.org/scripts/filter_tree.html, in order to only show tips in my dataset, but I’m not sure if this script will work in Qiime2. Is there a better option?

As well, this script requires a fasta file input. I have my sequence & taxa information in a .csv file, how do I convert it to a .fsn?

Victoria