Run the Design manager on a schematic, refresh the Components view and scroll down to find that Q4 has no package assigned to it!
Click on Q4 in the list to bring it into focus:
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Click on the empty Footprint attribute field in the right hand panel to open the Footprint Manager:
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Search for, select and check the pin mappings of the desired footprint:
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then press Update and then Cancel to close the Footprint Manager.
Refresh the Components View in the Design Manager to see that the device now has a properly assigned footprint!
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Chrome
81.0.4044.138
Ubuntu
EasyEDA
6.4.0