To trade successfully, a landlocked country like Bolivia must make treaties with neighboring states that allow trade through their territory.
make war against neighboring states to gain sea access.
build airports to bring goods in and out of the country.
build canals that bring water trade into the country.
appeal to the United Nations to force other countries to let them trade.

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.