The constitution provides for Direct taxes ( taxes paid to the federal govt by the states in proportion to their population). It also provides for duties, imposts and excises. Duties and imposts are tariffs. Excise taxes according to the Law.com dictionary are defined as follows:
excise
n. a tax upon manufacture, sale or for a business license or charter, as distinguished from a tax on real property, income or estates. Sometimes it is redundantly called an excise tax.
As you can see they are not income taxes and are specifically distinguished from income taxes.
The term "indirect tax" does not come from the constitution. It has been used by statists to create something which the constitution does not provide for.
When did Article I Section 8 Clause 1 get amended?
That clause grants a broad Tax power, then limits what the money may be spent on, and then limits the manner in which Duties, Imposts and Excises can be imposed.
Clauses 4 and 5 of Article I Section 9 then places additional restrictions on the ability of Congress to tax by specifying how direct taxes are to be levied and baring taxes on exports.
Note that without the 16th Amendment, one could argue that Article I Section 9 Clause 5 bars the taxing of income derived from exporting goods.