You can use the background removal feature to separate the object from the background and easily make the background transparent.
Open ①[ Tool Select window ] and select ②[ Filter ].
Tap ③[ Smart ] and select ④[ Background Removal ].
Immediately after activating the background removal feature, it will be in the mode to specify the object. Tap the screen and specify the object you want to cut out. A ⑤[ blue knob ] will be displayed at the tapped point, and the target will be selected in blue.
If there is an unnecessary part selected, select the ⑥[ - (minus) button ] to switch to the background selection mode. When you tap the area you want to treat as the background, a ⑦[ red knob ] will be displayed and you can exclude it from the selection range.
When you turn off ⑧[ Show Mask ], you can check the state after cutting out the object. When you are done with the adjustments, tap the ⑨[ OK button ].
The background has been removed.