I had conneced my digital pin of arduino to the uln2803a to drive LED. I want to configure my uln2803a such that i can connect +ve side of the led to the output pin of uln2803a IC.
ULN2003 only sinks current (connects load- to Gnd). It does not source current (connect load+ to +5). For that, you need a part like MIC5891, which is a shift register with high current source outputs. https://www.digikey.com/product-detail/en/microchip-technology/MIC5891YN/576-1310-ND/771779
If you don't need that much current, or the latch capability from the shift register, then a line driver such 74AC541 can drive 24mA loads https://www.digikey.com/product-detail/en/texas-instruments/CD74AC541E/296-4248-5-ND/375631
Or other parts in the 74AC family if you need something in a smaller package https://www.digikey.com/products/en/integrated-circuits-ics/logic-gates-and-inverters/705?k=74ac&k=&pkeyword=74ac&sv=0&pv69=80&sf=1&FV=ffe002c1&quantity=&ColumnSort=0&page=1&stock=1&pageSize=25
ULN2003A cannot be used as a high-side driver, however you can use it to drive a PNP transistor or a MOSFET per channel.
Pick R2 to give about 1/20 the LED current to the base and pick R1 something like 1K to prevent leakage from turning the transistor on.