Short answer: No.
Super Mario Maker 2 is a Nintendo Switch exclusive. PPSSPP is a PSP emulator, and it cannot run Switch, DS, or 3DS games. Any website claiming a "Super Mario Maker 2 ROM for PPSSPP" is lying or spreading malware.
While you can’t build Mario levels, the PSP has two excellent 2.5D platformers where you can create your own levels:
A quick search for “Super Mario Maker 2 PPSSPP download” will flood you with YouTube videos and sketchy websites claiming to have the file. Do not trust them.
These are almost always:
Bottom line: There is no safe, working Super Mario Maker 2 ROM for PPSSPP.
The PSP homebrew community has created dozens of unofficial Mario clones. Search for:
These require a modded PSP or PPSSPP’s homebrew folder, but they are not Mario Maker 2. super mario maker 2 ppsspp download
The Nintendo Switch is vastly more powerful than the PSP. It features a custom NVIDIA Tegra X1 processor, 4 GB of RAM, and runs on completely different architecture (ARM vs. the PSP's MIPS).
Attempting to run SMM2 on PPSSPP is like trying to play a Blu-ray movie on a cassette player. The file format, the processing power, and the operating system are entirely alien to one another.
If you download a file named Super_Mario_Maker_2_NSFW.ppsp.iso from a random forum, you are almost certainly downloading: Never search for “PPSSPP download Mario Maker 2” again
While you cannot play Super Mario Maker 2 on PPSSPP, you can play a fan-made "homebrew" game that attempts to replicate the classic Super Mario Bros. experience on the PSP.
If you truly want the "create, share, play" loop of Super Mario Maker, download LittleBigPlanet (LBP) for PSP.
How to get LBP on PPSSPP: