The setting of this world is a galactic zoo in which numerous species of sentient aliens coexist at a primitive tech level. Each species can be assumed to have their own language and therefore understand symbolic representations of meaning along with the basics of logic and mathematics. Assume as well that they are at least as generally intelligent and adaptable as humans and are capable of using tools. However, the biology of these organisms differs radically between species. While they are all carbon-based and capable of surviving in an earth-like environment most will not be capable of making vocalizations in overlapping ranges or even vocalizing at all so a simple spoken language is out of the question. Some species may be blind and others deaf. Some species may lack appendages useful for signing or at least have different enough appendages that translating movements directly would be challenging.
How do you construct a universal language agnostic to biological differences between its users?
As each species mostly keeps to itself the lingua franca is primarily used for bartering and negotiating between groups so it’s acceptable if it is clunky and slow. Importantly this question is different from previous, similar questions due to the primitive tech requirement. There are no computers to automate any translations.
Edit: To address concerns about "commonality of sensorium" and to narrow the scope of the question and make it a little less "neat" let's establish some senses the aliens will have in common:
An ability to, at range, determine the shape of their surroundings. This could take the form of sight, echolocation, radar, or any other technique that permits a fine, three-dimensional understanding of their environs.
A sense of touch that permits the aliens to differentiate between solid and gas and therefore feel the shapes and sizes of their immediate surroundings.