Make a new temporary layer. Use Gradient in the direction and the length according to the object you want to fill in with gradient. Switch to the original layer and use "Magic Wand" to select the region you want to fill in. Keep the selection and switch to the temporary layer. Copy the selection. Switch again to the original layer and paste.
Gradient Fill ?
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Make a new temporary layer. Use Gradient in the direction and the length according to the object you want to fill in with gradient. Switch to the original layer and use "Magic Wand" to select the region you want to fill in. Keep the selection and switch to the temporary layer. Copy the selection. Switch again to the original layer and paste.
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