If they accept your offer of peace and open their gates, all the people there will become forced laborers to serve you.
KJV
And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, [that] all the people [that is] found therein shall be tributaries unto thee, and they shall serve thee.
ASV
And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, that all the people that are found therein shall become tributary unto thee, and shall serve thee.