Do you go directly to apply for a visa or go to the immigration office after receiving the invitation from a listed company in Singapore?

Yes, but you don't have to go to the Beijing embassy. You can go to the consulate nearby. You must bring all your documents 1 when you go to Shanghai. Keep at least one blank passport (if not, go to the exit-entry management office of the local public security bureau). 2. A copy of the original household registration book and ID card. 3. Copy of the original relevant certificate (you are the invitation letter). 4. Two photos of certificates taken in March recently, with white background. You'd better take other documents, just in case. In your case, Singapore had better contact the consulate in advance, so it will be easy. Are you satisfied?