Is there a way to enter a csv file for crypto earnings into a 2018 ammendment instead of typing all the transactions

At tax time, you have the option to summarize your transactions by Sales Category.

IRS requires details to be listed on a Form 8949,
or on your other forms (e.g. consolidated 1099-B) which have the same information and in the same manner as Form 8949.
Either way, if you choose to summarize, you have to mail the transaction details to the IRS within three business days of IRS accepting your e-Filed tax return.(unless you have attached a PDF of the transactions details to your e-Filed return. TurboTax seems to be adding this feature now).
Exception: if you summarize Category A or Category D, Form 8949 is not needed for transactions without adjustments. No mailing is necessary.

If you don't have a 1099-B because it is crypto, your sales category is C or F.

There is no exception for these categories.

Edit your csv to add a column title row identifying the items from Form 8949.

Recommended to rearrange columns in the order shown on Form 8949.

Also put your Name and SSN and tax year.
Your return will still have Forms 8949 to e-File but they will have subtotals instead of each individual transaction.

Print and mail the csv to the specified IRS address for that purpose.

a 2018 amendment must be filed on paper,

so include the csv printout at that time with your 1040-X.

you are filing for 2018 which can not be e-filed.  so on form 8949 include a summary of the transactions. print out the CSV file - it needs to be in a format somewhat similar to the form 8949 and include it with your mailed return.