Val Packett has already made a PWA version of TiddlyWiki, it works very well !
You can try it here: TiddlyPWA — TiddlyWiki Storage & Sync Solution. To enable sync between devices, you will need to follow the tutorial for glitch (easy and fast, but glitch make the server sleep every so often) or host a deno server yourself. I have made my own tutorial to host a server on a raspberry pi: Setup your own TiddlyPWA server on Raspberry Pi 5 (using cloudflare tunnel)