Updated with more insight
I've kept in touch with a senior manager in order to keep a lead for some job in a year or so (just started a new one).
I emailed him recently to know things went on his side and expressed the fact that I'd be interested to join him at some point.
I think he might have misunderstood and proposed me in his last email to send him my resume as they are thinking of opening some roles in his company.
How would you answer so I don't lose that lead? As I also cannot update my resume quickly (will take me a month), how would you tell him that I'd need more time too to send it to him?