<TextField

    classes={{ root: classes.root }}

    select

    name="userRoles"

    id="userRoles"

    variant="outlined"

    label="userRoles"

    SelectProps={{

      multiple: true,

      value: formState.userRoles,

      onChange: handleFieldChange

    }}

  >

    <MenuItem value="admin">Admin</MenuItem>

    <MenuItem value="user1">User1</MenuItem>

    <MenuItem value="user2">User2</MenuItem>

  </TextField>