How can i get selected value from Db in react multiselect dropdown

This is my code .I want to get selected option from db

<Select placeholder={"Select Mates"} onChange={handleChange} options={data.map(e => ({ label: e.UserName, value: e.Id}))} isMulti required="true" theme={theme => ({ ...theme, colors: { ...theme.colors, neutral50: 'white', }, })} />