As @XRaTiX says, the package is in the AUR, so you needn’t bother with what you are doing. However ─ just for the record and for educational purposes ─ just because a file has execute permission for you doesn’t mean you can execute it by simply typing its name at the command prompt.
Unlike in Microsoft Windows ─ which still carries an awkward amount of legacy from MS-DOS and CP/M ─ the current working directory is not in the $PATH by default, and shouldn’t be. Therefore, if you want to execute a file that’s not in one of the directories of the $PATH, then you must prepend the filename with either an absolute or relative path to the file. A few examples follow…
I’ll just wait for the package to download, then if I didn’t encounter any issue regarding the installation, I’ll just choose @XRaTiX’s answer as the solution