I'm just a solo tourist.

Is it mandatory that an invitation letter from sponsor be provided when applying for an Hong Kong tourist visa?

Do I need to apply at Abuja or Lagos?

I appreciate your contribution.

Actually you need invitation lette from your host. Moreso, you need to know that it is china embassy either in lagod or abuja. Visit their website. Their address in abuja it not far from us embassy in maitama abuja. If you need more question dont hestitate to ask here so that people can do justice to your question.