問題
My dog-sitter’s brother made this website but I can’t get in; can you help?
解法
開啟F12，按到原始碼，index.js在後面的部分有Your flag is......可以得知當「密碼正確」時就會顯示前面的cGljb0NURns1M3J2M3JfNTNydjNyXzUzcnYzcl81M3J2M3JfNTNydjNyfQ
cGljb0NURns1M3J2M3JfNTNydjNyXzUzcnYzcl81M3J2M3JfNTNydjNyfQ
老師有說過這是base64編碼，所以
答案
picoCTF{53rv3r_53rv3r_53rv3r_53rv3r_53rv3r}