$5000 at the end of the week? That's possible but I am not gonna offer you anything. It's basically on how you're quick to complete something. Why not look at the websites like Upwork, fiverr and anything of the same? Those employers or projects that look for results based skill since you're a senior full stack developer. You are for sure aware of deadlines and I think that's your best asset right now but you just need to find the right client that has projects on works so, do your search now with those platforms that I've mentioned and others that has the same freelance market place. Might find one as well on subreddits related to crypto/freelancing.
e.g.
I need to make $5000 until the end of the week. I am a senior fullstack software developer, also I have strong knowledge in blockchain. Except the software development I am willing to do everything as a job. I am looking short and longterm job opportunities.
Let me tell you right now, you'd better look for another way to get that $5,000 or start coming up with an excuse as to why you don't have it at the end of the week.
Even if you start a deal with someone, by the end of the week you will not be able to agree on all the conditions and requirements of the job. Plus you need to finish all of that to be paid in full.
How did you imagine it, you just fly here
from nowhere, nobody knows anything about you, collect $5000 and leave.
I see that you tried to sell Pi coin earlier, why don't you sell it and solve the financial problem you have?
I will finish the job before receiving the payment. I'm not here to grab the money before I do my job. Unfortunately I didn't know that Pi coins have no market yet.