Fungi cannot make their own food through photosynthesis. how do they take in nutrients?

Fungi use enzymes to break down the materials on which they are growing . when they absorb digested material , the food would be  in the form of a solution in order to enter the hyphal walls of the fungi
.  In general, fungi require oxygen to survive, but they are also able to use fermentation when they lack oxygen

Fungi are heterotrophs which  means that they acquire their nutrients from other sources and can not make their own food. Fungi mostly release enzymes in their surroundings which break down the nutrients which are later on taken up by the Fungi.