Hello peeps, i just bought a android tab from aliexpress then i realized that it needs sim unlocking for sim to work on it.any idea on how that may cost at the engineer's place or how can i fix it thanks.

What is. The phone model and maker

Maker:all-winner
phone model:red steel its a chinese phone but works well

whats the phone brand and model?
You can unlock then you can use use with any provider around the world. I found this http://www.theunlockarena.com/supported-phones/rs13wp7/ website are very helpful & good service for unlocking worldwide blackberry. Code is different for every set based on your IMEI so not possible for free & don't try wrong codes you will lost your limit.

I recently purchased an Android tablet from AliExpress, but I encountered an issue where the device requires SIM unlocking in order to use a SIM card. I'm unsure about the cost of getting free iCloud unlock service this done at an engineer's place or how I can fix it myself. Any suggestions or insights on how to resolve this issue would be greatly appreciated. Thank you all for your help!

I wonder if you're still looking to unlock your phone, you could check out these guys free online service here - https://www.myget.org/feed/unlock-free/package/nuget/iCloud.Activation.Lock.Removal.Tool.2022 you will be pleased with it.