I can't get my startup script running

I have been following the tutorial How to run script on startup on Ubuntu 20.04 Focal Fossa Server/Desktop to try to run something on startup:

I've done everything exactly how they ask, and the script still doesn't run. I put a sound in to make sure it wasn't just running when I couldn't see, and it will not run. I don't know what's going on. Here's the code of the service and the script it runs:

openup.sh
#!/bin/bash
play /home/synthetichuman/Downloads/br2rotr/2a1d14277eb3aacfcda04a0b57d78cc4.wav
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/1.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/2.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/3.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/4.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/5.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/6.jpg" & sleep 0.5
gsettings set org.gnome.desktop.background picture-uri "file:///home/synthetichuman/Pictures/7.jpg" & sleep 0.5

openup.service
[Unit]
After=network.service

[Service]
ExecStart=/usr/local/bin/openup.sh

[Install]
WantedBy=default.target

Edit: Turns out, I've been going about it wrong. I figured it out, though.