In the block diagram, right click & add IP -> Type MIG in the search tab -> double click Memory Interface Generator.
Double click the "memory Interface Generator" block and then select the type of memory (DDR2/DDR3/DDR4 etc) and apply the relevant configurations.
Export/Make external all the DDR memory IOs. The user interface can be connected to relevant native/AXI MM interface masters in the block design or user interface can be exported from the block diagram to connect it to any module outside the block diagram.
You can get many video example designs for ZCU102/ZCU104/ZCU106 platforms which uses DDR4 in the block design.