To enter Ukraine, citizens from some countries can get an e-visa.

However, to obtain it, in addition to the insurance policy and other documents, you must have a document that serves as the basis for entry, usually an invitation letter.

Without it, you will not receive a visa.

For different purposes, you can issue different documents:

Business e-visa

When applying for an electronic visa for traveling for business purposes, one of the following documents is submitted:

1. invitation of a legal entity registered in Ukraine, executed in accordance with the established special rules;
2. invitation of the state body, state institution, state enterprise, state organization;
3. a document confirming the implementation of foreign investment in accordance with the legislation on the mode of foreign investment in Ukraine.

More information:

https://immigration-ukraine.com/invitation-for-e-visa-to-ukraine/