How to set a DPI higher than 300 when uploading images to PS CC 2020 from SD card

Check/click your Adobe Camera Raw Workflow Options hyperlink text at the foot of the window/interface.

The image has a fixed number of pixels; that's all that matters in terms of the import. PPI has absolutely no role in quality per se. It is simply a resolution tag. The tag provides a possible size IF used to divide up those pixels. 

The tag could be 72PPI or 180PPI or 300PPI or higher, but it doesn't have an inherent meaning, only what you could produce with the number of pixels you have at your disposal. Work with pixels! For example, let us say you have 1000x1000 pixels to keep the math simple. And to simplify this further, let's only consider the horizontal axis. If you have 1000 pixels and divide that by 72, that is, you provide 72 pixels per inch, you could end up with 13.8 inches using that division (1000/72=13.8). Let's now say you divide up your 1000 pixels using 180 instead. 1000/180=5.5. In both cases, you had 1000 total pixels. The document itself doesn't have a size, other than what space it takes up on your hard drive. The sizes above are examples of what could be produced if you divided up the total number of pixels you have, with some number of which is just a tag within the document. In Photoshop, if you use the Image Size dialog, turn resample OFF (do not allow it to create more or remove pixels), you can enter any value, 72, 180, 1000 into the resolution field and the resulting size is calculated for you. But you haven’t changed the document or the data at all. You just changed a theoretical 'size' if you output your 1000 pixels using that resolution. So again, it's meaningless until you output the data. At that point, lets say you print the image, you can decide how big you wish it to appear and/or how many pixels you want to devote to the output. You have 1000 pixels and someone tells you that you must use 300DPI (which isn't true but that's a different story). 1000/300 would produce a 3.3 inch print.

You need to understand that ppi - not dpi - is not a property of the file. It's metadata. Ppi can be as high or low as you like and it doesn't change a thing.

Pixels per inch, ppi, is strictly a print parameter. It means exactly what it says: how many pixels per inch of paper.

Now, in ACR (I assume you're talking about raw files from a camera) you have the option to upsample the file to higher pixel dimensions. That is not something you want to do unless you have very good reasons. Upsampling is always harmful to the file's integrity and quality. Very few cases justify the reduced quality.