Every time while enumerating a web page, it is a good practice to taka a look at the *robots.txt* file.
Think you have seen your flag or want to keep looking.
We can see, that the gibberish inside looks like base64 code, so using CyberChef we can decode:
ZmxhZzEudHh0 from base64: flag1.txt
anMvbXlmaWxlLnR4dA== from base64: **js/myfile.txt**
Now go to url http://saturn.picoctf.net:65352/js/myfile.txt for a flag.