Variable _0x5140b1 has the character "~" in front of it. I don't know what it is intended for. I tried looking it up but I couldn't really find any sources on it.
for (
let _0x14ee70 = 0x0, _0xc69fbd, _0x5140b1, _0x3d83e7 = 0x0;
(_0x5140b1 = _0xec6c25["charAt"](_0x3d83e7++));
~_0x5140b1 &&
((_0xc69fbd =
_0x14ee70 % 0x4 ? _0xc69fbd * 0x40 + _0x5140b1 : _0x5140b1),
_0x14ee70++ % 0x4)
? (_0x4f1900 += String["fromCharCode"](
0xff & (_0xc69fbd >> ((-0x2 * _0x14ee70) & 0x6))
))
: 0x0
) {
_0x5140b1 = _0x2f20af["indexOf"](_0x5140b1);
}