patternfly-ToolbarItem-Dropdown.js

import imgAvatar from '@patternfly/react-core/src/demos/assets/avatarImg.svg';

<ToolbarItem visibility={{
    default: 'hidden',
    md: 'visible'
  }}>
          <Dropdown isOpen={isDropdownOpen} onSelect={onDropdownSelect} onOpenChange={isOpen => setIsDropdownOpen(isOpen)} popperProps={{
    position: 'right'
  }} toggle={toggleRef => <MenuToggle ref={toggleRef} onClick={onDropdownToggle} isFullHeight isExpanded={isDropdownOpen} icon={<Avatar src={imgAvatar} alt="" />}>
                Ned Username
              </MenuToggle>}>
            <DropdownList>{userDropdownItems}</DropdownList>
          </Dropdown>
        </ToolbarItem>

const onDropdownToggle = () => {
    setIsDropdownOpen(!isDropdownOpen);
  };
  const onDropdownSelect = () => {
    setIsDropdownOpen(false);
  };