If auto gather is turned off, there is currently no way to manually gather (at the moment).
There is a full listing of all the controls in the help/hint dialog. Here’s it copy/pasted:
MovementTo move, you are able to use W,A,S,D, arrow keys, VI keys (H,J,K,L), or by left clicking on the game screen in the direction you want to move. To skip/pass a turn, or to pick up item(s) on the tile you are standing on, press the spacebar or left click your character on the game screen.Using ItemsTo use an item, you may double click it anywhere in your inventory, equipment, or within quickslots. Additionally, you are able to drag and drop an item into one of the quickslots. Press the number (1, 2, 3, etc.) that corresponds with which quickslot it is attached to.Item Uses, Dropping and InformationSome items have secondary uses which require you to right click them to activate their special effects (described in the tool-tip of the item). If the item has no secondary uses, or cannot be interacted with the tile you are facing, you will drop the item down on to the ground. If you are facing a container, you will drop the item inside. You can use control + right click to drop multiple items of the same kind. Additionally, you are able to right click on the game screen to reveal information about what you are clicking on whether it be items, monsters, tiles, and more.More InformationHovering over elements on screen will typically reveal more information. Tool-tips will appear over items. Hovering over crafting items will highlight items used in the craft.Item ManagementBesides dragging and dropping items to your quickslots, you are also able to equip items in this fashion, provided it is an equipment item and fits in that slot. Dragging and dropping is also required to move items your container window and inventory (besides right clicking to drop an item into a container on the ground). Additionally, Right clicking an item in your equipment list, quickslots or container window will remove it to your inventory.Window ShortcutsEsc = Main MenuI = Inventory/ = HelpC = SkillsM = MessagesO = Options