You can Accept a Quote via AcceptQuote End point.
Below for the required field to accept the Quote.
{
"QuoteNo": "Q005218v2",
}
If you required to Create an Invoice after you accept a Quote, then you can pass the payload as per below.
{
"QuoteNo": "Q005218v2",
"CreateInvoice": true,
"CreateInvoiceAsPaid": false,
"CreateInvoiceAsInternallyInvoiced": false
}