May I know are you going to decline their offer or would like to think for a few days? If you're decline, you can simply state reason why you're declining their offer but if you would like to get a few days to think, you can reply and ask them give you 3 days for you to think pro & cons. Ensure that you give them the exact date and reply them accordingly. I hope my answer give you a clear mind.
there is always a chance, dont give up
One thing about finding a job, you gotta have to get used to rejection. because it's normal, and it's also normal to get frustrated however do not dwell in it, what you got to do, is to find out things that you can improve such as learning new skills, or check back your resume, create a connection in LinkedIn and so on. There's a lot of ways to find a job, not only by going through a job portal.
I wish you all the best from Maukerja Team!
在职场上不一定可以结交到朋友，但是拥有基本的人脉是非常重要的。