This little trick can make your Widget invisible on iOS 14

 Step 1: Install the Smith and Scriptable Widget apps from the AppStore store.

• Download it right here: WIDGET SMITH
• Download it right here: SCRIPTABLE

Step 2: After installing 2 apps, you need a blank screen shot. Hold on any empty space on the screen to enter Edit mode> Then swipe left to open a blank screen> Press the power button and volume up at the same time to capture the screen.

Step 3: Copy the code in the link below> Then open the Scriptable application> Click the plus sign (+) on the right> Paste the code> press the play button.

Copy the code here.

Step 4: After pressing the play button, there will be a bulletin board, press Continue> Go to photo album, select the screenshot taken in step 1.

Step 5: Continue to choose the Widget size> Choose the location to place the Widget to match the background image as above, in the middle and below with large, medium and small sizes.

Step 6: Click on Export to Photos to finish and complete the steps.

Step 7: After installing the Widget configuration, open the Widget Smith app> Select the Widget size that you installed in step 5> Click Default Widget.

Step 8: In the Style section, scroll down to choose any Widget style you like  

Step 9: Click Selected Photo, click Choose Photo, select the photo created from Scriptable> Save.

Step 10: At this point you just need to add the Widget as usual. In the Widget page, select Widgetsmith, choose the size and it's time to create the widget, click Add widget.

Step 11: Drag the Widget to the selected position at first, you will see that the Widget's background will be transparent and become one with the desktop.

Good luck.